Instruments - Science topic

The article "Validity and Reliability of Measurement Instruments Used in Research" by Carole L. Kimberlin and Almut G. Winterstein emphasizes the importance of reliability and validity in research instruments for accurate and consistent data collection. It emphasizes the development and validation process, reliability estimates, validity, responsiveness to change, and data accuracy, particularly in healthcare and social science research, where accurate and reliable instruments are crucial for quality research.

We are an R&D laboratory focused on anionic, cationic, and zwitterionic surfactants and usually tackle surfactant synthesis and analysis of products from customers. In particular, we deal with AOS (alpha-olefin sulfonates), primary alcohol sulfates, betaines, amphoacetates, amine-oxides.. etc. To gear our analytical laboratory up, we identified an HPLC-MS (single quadrupole) instrument as a valuable addition to comply with unmet needs that have risen in the last years, like figuring out the outcome of the new reaction and investigating byproducts and new raw materials. Currently, we are evaluating three choices: Agilent LC/MSD, Waters Acquity Arc System (with Qa Acquity Detector), and Shimadzu LC-MS2050. Could anyone in this field share their experiences with these instruments? and suggest which of them is the most reliable for this application. Thank you so much for your attention and participation.

I am looking for an instrument to study the Sustainable Leadership (Andy Hargreaves's) of school Principals and its effect on Teachers' Productivity. I noticed quite several studies and research papers on the topic but, I am looking for anyone who has access or knowledge, and is willing to share any instrument that I can cite and use in my dissertation.

Thank you very much in advance.

Hi there,

I am a Masters of Education (Leadership) student, in the early stages of completing my thesis, exploring the link between emotional intelligence and school leadership style. As part of this research, I would ideally like to use the Mayer Salovey Caruso Emotional Intelligence Test (MSCEIT) instrument. I will be conducting a qualitative study (interview), which will incorporate the use of a psychometric tool. I hope to interview about 15 school leaders.

I am, however, finding it difficult to figure out how to access this tool. I appreciate that I will have to buy a license to use the instrument. Would anybody have experience in requesting this license? Or, perhaps a similar instrument which might prove easier to access (which would be applicable to an educational setting.)

Many thanks in advance!

Amy

I am studying leadership style's impact on job satisfaction. in the data collection instrument, there are 13 questions on leadership style divided into a couple of leadership styles. on the other hand, there are only four questions for job satisfaction. how do i run correlational tests on these variables? What values do i select to analyze in Excel?

These terms are all related to the evaluation of research instruments, particularly surveys and questionnaires. Here's a breakdown of each:

Cronbach's alpha (α): This is a widely used statistic to assess the internal consistency or reliability of a test or scale. It essentially measures how closely related the items in your survey are to each other. High Cronbach's alpha indicates that the items are all measuring the same underlying concept and provide consistent results.

Average Variance Extracted (AVE): This statistic is used to assess the convergent validity of a construct in a structural equation model (SEM). Convergent validity shows how well the indicators (survey questions) represent the underlying construct they are intended to measure. A high AVE value suggests that a greater proportion of the variance in the indicators is due to the intended construct, rather than measurement error.

Composite Reliability (CR): Similar to Cronbach's alpha, CR is another measure of internal consistency in the context of SEM. It reflects the reliability of the composite score derived from multiple indicators. A high CR value indicates that the composite score is a reliable estimate of the underlying construct.

I am writing my dissertation and I am thinking of using an exploratory sequential design. I intend to collect a qualitative data that will inform my quantitative study. My intention is to use the information from my qualitative data to construct a Quantitative instrument but I may not be able to test the instrument due to time constraint. How best can I describe the method I am trying to use. I would also appreciate any literature out there that can be helpful to guide me. Thank you!

What is a super vacuum? Is the earth in a vacuum? And what is dark energy?

It has not been proven until today and nature has always applied and proven exceptions and violations in the accepted theories many times in the past. That these were merely human formalisms and experimental artifacts and exploiting the limits of technology, and physical limits and laws are constantly being broken and bent in nature. Hereby we will attempt to show theoretically why and how there is and experimentally evidence in our universe of vacuum space, either in its theoretically idealized absolute form, thus free space or the partial vacuum that characterizes the vacuum of QED or QCD. And its zero-point energy and oscillations may actually be the greatest proof in nature for super energy.

It is possible without violating causation. that the apparent effect of "nothing" of vacuum space may be evidence for it

superluminocity and all this time it was hidden right in front of us. We are here trying to answer a fundamental question of physics, why the vacuum is basically space to us looks like nothing on the assumption that "nothing" exists in nature, and why a hypothetical superluminous vibration, a particle the size of Planck creates apparent nothingness in our spacetime. The novelty of the research here infers that free space is dark energy and that superluminous energy.

Stam Nicolis added a reply:

(1) Depends what is meant by ``super vacuum''. The words must, first, be defined, before questions can be asked. As it stands, it doesn't mean anything.

(2) To a good approximation the earth is moving around the Sun in a vacuum, i.e. its motion can be described by Newtonian mechanics, where the only bodies are the Earth and the Sun and the force between them is Newton's force of gravitation.

(3) Dark energy is the property of space and time that describes the fact that the Universe isn't, simply, expanding, but that this expansion is accelerating. To detect its effects it's necessary to measure the motion of bodies outside our galaxy.

To understand all this it's necessary to study classical mechanics-that leads to understanding the answer to the second question-and general relativity-in order to understand the answer to the third

László Attila Horváth added a reply:

Dear Abbas Kashani ,

The graviton - which creates or capture elementary X-rays and gamma rays- , by itself, it can be considered almost like a super vacuum.

Sergey Shevchenko added a reply:

What are rather numerous, and really strange, “vacuums” in mainstream physics, and what are two real vacuums is explained in the Shevchenko-Tokarevsky’s Planck scale informational physical model , 3 main papers are

https://www.researchgate.net/publication/367397025_The_Informational_Physical_Model_and_Fundamental_Problems_in_Physicssection 6. “Mediation of the fundamental forces in complex systems”

https://www.researchgate.net/publication/369357747_The_informational_model_-Nuclear_Force.

The first vacuum is the Matter’s fundamentally absolute, fundamentally flat, fundamentally continuous, and fundamentally “Cartesian”, (at least) [4+4+1]4D spacetime with metrics (at least) (cτ,X,Y,Z, g,w,e,s,ct), which is the actualization of the Logos set elements “Space” and “Time” [what are “Logos” set, “Space” and “Time” see first pages in 1-st or 2-nd links] at creation and existence of a concrete informational system “Matter”,

- i.e. this vacuum is a logical possibility for/of Matter’s existence and evolving, and so is by definition nothing else than some fundamentally “empty container” , i.e. is “real/absolute” vacuum.

The second vacuum, which can be indeed rationally called “physical vacuum”, is the Matter’s ultimate base – the (at least) [4+4+1]4D dense lattice of primary elementary logical structures – (at least) [4+4+1]4D binary reversible fundamental logical elements [FLE], which is placed in the Matter’s spacetime above;

- while all matter in Matter, i.e. all particles, fields, stars, galaxies, etc., are only disturbances in the lattice, that were/are created at impacts on some the lattice’s FLE. At that it looks as rather rational scientifically to assume, that such vacuum really existed – that was the initial version of the lattice that was created/formed at the “inflation epoch”, more see the SS&VT initial cosmological model in section “Cosmology” in 2-nd link.

After this initial lattice version was created, in the lattice a huge portion of energy was pumped uniformly globally [and non-uniformly locally], what resulted in Matter’s “matter” creation, which we observe now.

Since all disturbances always and constantly move in the lattice with 4D speeds of light, now can be only some “local physical vacuums”, etc.;

- though that is really quite inessential – the notion “physical vacuum” is completely useless and even wrong, since the really scientifically defined FLE lattice is completely enough at description n and analysis of everything that exists and happens in Matter. The introduced in mainstream physics “vacuums” really are nothing else than some transcendent/mystic/fantastic mental constructions that exist in mainstream physics because of in the mainstream all fundamental phenomena/notions, including “Matter”, “Space/space”, “Time/time” are fundamentally transcendent/uncertain/irrational,

- while these, and not only, really fundamental phenomena/notions can be, and are, really rigorously scientifically defined only in framework of the SS&VT philosophical 2007 “The Information as Absolute” conception, recent version of the basic paper see

- the SS&VT physical model is based on which.

More see the links above, a couple of SS posts in

https://www.researchgate.net/post/What_is_the_concept_of_quantized_vacuum_And_what_is_the_role_of_gravity_in_nature_And_what_is_the_relationship_between_dark_energy_and_quantum_gravi are relevant in this case also.

Abderrahman el Boukili added a reply:

Super vacuum, in my view, is just the vacuum itself, that is, the channel through which the universe of particles and anti-particles intersects.

Courtney Seligman added a reply:

For all practical purposes, the Earth is moving through a vacuum as it orbits the Sun, as there is so little of anything in any given place that only the most sensitive instruments could tell that there was anything there. But there are microscopic pieces of stuff that used to be inside asteroids or comets, and pieces of atoms blown out of the Sun as the Solar Wind, and cosmic rays that manage to get through the Sun's "heliosphere" and run into anything that happens to be in their way. So though the essentially empty space around the Earth would qualify as a vacuum by any historical standard, it isn't an absolutely perfect vacuum. And I suppose a "super vacuum" would be a region where there isn't anything at all, including not only matter, but also any form of energy (which has a mass equivalence of sorts, per Einstein's Special Theory of Relativity); and if so, then "super vacuums" do not exist.

Harri Shore added a reply:

The concepts you're exploring—super vacuum, dark energy, and the nature of the vacuum in quantum electrodynamics (QED) and quantum chromodynamics (QCD)—touch on some of the most profound and speculative areas in modern physics. Let's break down these concepts to provide clarity and context for your inquiry.

Super Vacuum

The term "super vacuum" is not widely used in mainstream physics literature but could be interpreted to mean an idealized vacuum state that is more "empty" than what is typically considered achievable, even beyond the vacuum state described by quantum field theories. In standard quantum field theories, a vacuum is not truly empty but seethes with virtual particles and fluctuates due to quantum uncertainties, known as zero-point energy.

Is the Earth in a Vacuum?

The Earth is not in a vacuum but is surrounded by its atmosphere, a thin layer of gases that envelops the planet. However, outer space, which begins just beyond the Earth's atmosphere, is often described as a vacuum. This is because outer space contains far fewer particles than the Earth's atmosphere, making it a near-vacuum by comparison. It's important to note that even the vacuum of outer space is not completely empty but contains low densities of particles, electromagnetic fields, and cosmic radiation.

Dark Energy

Dark energy is a hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe. It is one of the greatest mysteries in modern cosmology, making up about 68% of the universe's total energy content according to current observations. The exact nature of dark energy is still unknown, but it is thought to be responsible for the observed acceleration in the expansion rate of the universe since its discovery in the late 1990s through observations of distant supernovae.

Vacuum Energy and Superluminosity

Vacuum energy refers to the energy that exists in space due to fluctuations of the quantum fields, even in the absence of any particles or radiation. It is a manifestation of the Heisenberg uncertainty principle in quantum mechanics, which allows for the temporary creation of particle-antiparticle pairs from "nothing."

The concept of superluminosity or superluminal phenomena (faster-than-light phenomena) is speculative and not supported by current mainstream physics, as it would violate the principle of causality, a cornerstone of the theory of relativity. However, there have been theoretical explorations of conditions under which apparent superluminal effects could occur without violating causality, such as in the context of quantum tunneling or warp drives in general relativity.

Vacuum Space as Evidence of Superluminous Energy

Your hypothesis suggests that vacuum space or "nothingness" might be evidence of a superluminous energy or vibration at the Planck scale that creates the apparent emptiness of space. This is a speculative notion that would require new theoretical frameworks beyond the standard model of particle physics and general relativity. It also implies that dark energy, the force behind the universe's accelerated expansion, could be related to this superluminous vacuum energy.

While current physical theories and experimental evidence do not support the existence of superluminous phenomena or energies, the history of science shows that our understanding of the universe is constantly evolving. Theoretical proposals that challenge existing paradigms are valuable for pushing the boundaries of our knowledge and prompting new avenues of experimental and theoretical investigation. However, any new theory that proposes mechanisms beyond established physics must be rigorously tested and validated against empirical evidence.

Courtney Seligman added a reply:

1. A vacuum is a region of space with no matter; a super vacuum could be defined in one of two ways, depending on whether it is a concept, or a description of current technology. In the first instance, it with be a region of space with neither matter nor energy (in which case, unless an extremely small region, it does not exist, because any part of space big enough to see without a microscope would at least have light of some sort passing through it (e.g., at least the Cosmic Background Radiation). In the second instance, it could be used to describe a "laboratory" vacuum which has far less matter in it than any previously created laboratory vacuum.

2. The Earth is in a region that is essentially a vacuum, because most of the space between the planets has practically nothing in it at any given time. However, there are cosmic rays and the Solar Wind everywhere, so though merely pieces of atoms, there is some stuff everywhere in space; but the amount is so small that for all "practical" purposes, it is a vacuum.

3. Dark energy is a fiction created by cosmologists to explain why, despite having too little mass for the gravity of that mass to fight the tendency of empty space to expand (per Einstein's General Theory of Gravity), the geometry of the Observable Universe is "flat", which would require something to add up to 100% of the "critical mass" of the Universe, and since visible and unobservable ("dark") matter makes up at most 27% of the critical mass, cosmologists created the concept of dark energy to make up the remaining 73%. However, there is no need to presume that the Universe is flat. Just as the Earth is a globe but looks essentially flat (on the average, and particularly at sea) because you can't see enough of it to see its real shape, the Universe is actually what is called "hyperbolic" in shape, which is exactly what you would expect if its mass is less than the "critical" mass. However, almost all cosmologists are convinced by various characteristics of the Observable Universe that the "real" Universe is at least 1000's and perhaps 10 to the 1000's of times bigger than what we can see, what we can see is too small to see its real shape, so it just looks "flat". Since by definition we can't see anything but the "Observable" Universe, we will never be able to see the true shape of the Universe; so "dark energy" will remain a "useful" fiction for calculation purposes for the foreseeable (if not infinite) future; but I am certain that we will never figure out what it is, because it doesn't exist. (Having been both a mathematician and a professional astronomer, I can assure you that even when something like "dark energy" doesn't exist in real life, creating a mathematical model that includes it, in order to make the math work right, is considered perfectly OK by professional mathematicians.)

Abbas Kashani added a reply:

Introduction The ‘Theory of Everything’ is a hypothetical theory of physics that explains and connects all known physical phenomena into one. There is a possible solution to the origin of gravity force, postulating it as angular piece of this theory, this solution erases gravity as one of the fundamental forces of nature and unifies it with strong nuclear force. Let’s analyze the forces that occur in the universe transforming string theory. It allows to explain many physical behaviors that without its existence would be practically impossible to understand, even so, these strings have not been able to be discovered and are only that, a theory that serves as an important support to the world of physics. One of the best known theoretical applications about them is how their vibration can provoke the creation of matter, but this is not about theories already written, we are going to place these strings in a simpler way to answer some doubts in subatomic world. This theory uses 4 dimensions in space and a behavior as one dimension in strings with superconducting capacities. Like an elastic band between V-shaped sticks where the elastic band slides down, the strong nuclear force, forces these strings to bend to fall dawn.

It’s not directly related to electromagnetism. . Actors . String Theory String theory is a theoretical framework in which the point-like particles of particle physics are replaced by onedimensional objects called strings. Each string that we cross would be the minimum distance that can be traversed during a displacement. We can note two important qualities of strings: Distance to the most distant object detected by the human being is more than 30 billion light years, that means there are beams of light which are able to travel that distance without decreasing its speed (they modify only its wavelength). Like light, an object can move into space for a practically unlimited period, as long as it doesn’t find a force to stop it. If strings exist, they act as a superconductor of matter with a resistance near 0. In order to generate waves it’s easier into a strongly linked structure. Gravitational waves behave like ocean waves which are similar to an uptight net, these tensions can be decomposed as one-dimensional structure for its study. Strings, at same time, could be one or zero-dimensional, like points under extreme bound forces, think about them as something tenser than any cable that holds the heaviest bridge in the world. The new framework we have drawn would be a set of extremely tense strings, with a practically infinite matter conduction capacity. Remember we are moving into universe at a stimated speed of 600km/sc. Strong Nuclear Force Strong nuclear force is another variable. This force allows the atomic nucleus to remain together, being the strongest of the so-called fundamental interactions (gravitational, electromagnetic, strong nuclear, and weak nuclear). Gluon is in charge of this interaction, it has a scope not greater than 10 to the power of -15 meters, preventing matter to separate by a constant attraction force between quarks of maximum 10.000 N (F). This real picture illustrates the three dimensional structure of gluon-field configurations, describing the vacuum properties. The volume of the box is 2,4 by 2,4 by 3,6 fm.Contrary to the concept of an empty vacuum, this induces chromo-electric and chromo-magnetic fields in its lowest energy state. The frame rate into this example is billions of billions frames per second (FPS). Superconducting String Theory (SST): Fundamentals: superconductor of matter interacting with a force that makes that matter hold together, but, how can they interact with each other? The most simple is to think about two V-shaped sticks (simulating the strings), and an elastic band that tight them at the most opened side (it would simulate the gluon, with size 10 to the power of -15 meters). If sticks are sufficiently lubricated and tense, what does the elastic band do? It will slide to the thinnest side. More elastic bands, more force will be exerted on the sticks to join them, so next bands will slide even faster (equally, more mass causes more attraction). We are talking about unknown limits in known world, such as infinite conduction or tensions never seen in materials. Suddenly, we have erased one of the fundamental forces of nature, gravity force doesn’t really exist, exists the strong nuclear force interacting with strings. this theory ‘Superconducting String Theory (SST)’. Calculations: Apply formulas from inclined planes (Newton’s second law). Simulation is in horizontal direction. Friction is imperceptible and acceleration down the plane is matched with gravity acceleration in our planet. Vertical force is not gravity force, it is gluon force, which values ares estimated, so we keep force 10.000 N (F1) and mass 0,0002 eV/c2 (m2). It can be considered vertical angle, but it’s depreciable.Dark energy and universe’s expansion. The behaviuor of the strings implies to have any kind of polaritation to expand, at least, strong enough to avoid get closer and restablish its structure after any contraction. This strength propagates over long distances.Gravitational constant (G = 6,67408 × 10−11 m3 kg-1s -2) and its problem to measure with high accuracy since it can be related to the density exposed. Schrödinger equation, to describe how the quantum state of a quantum system changes with time, similar to Newton's second law. Planck's length (1,616229 × 10-35 m) which can indicate the distance between strings. Gluon size and its larger size far from earth. Black holes.and .....

Reply to this discussion

Mohammed H.Ali added a reply

Until date, there is no conclusive evidence to support this claim. Throughout history, nature has consistently shown exceptions and violations to widely accepted beliefs. These human formalisms and experimental objects are just abusing the constraints of technology. In nature, physical limits and rules are continuously being surpassed and manipulated.

What is a super vacuum? Is the earth in a vacuum? And what is dark energy?

It has not been proven until today and nature has always applied and proven exceptions and violations in the accepted theories many times in the past. That these were merely human formalisms and experimental artifacts and exploiting the limits of technology, and physical limits and laws are constantly being broken and bent in nature. Hereby we will attempt to show theoretically why and how there is and experimentally evidence in our universe of vacuum space, either in its theoretically idealized absolute form, thus free space or the partial vacuum that characterizes the vacuum of QED or QCD. And its zero-point energy and oscillations may actually be the greatest proof in nature for super energy.

It is possible without violating causation. that the apparent effect of "nothing" of vacuum space may be evidence for it

superluminocity and all this time it was hidden right in front of us. We are here trying to answer a fundamental question of physics, why the vacuum is basically space to us looks like nothing on the assumption that "nothing" exists in nature, and why a hypothetical superluminous vibration, a particle the size of Planck creates apparent nothingness in our spacetime. The novelty of the research here infers that free space is dark energy and that superluminous energy.

Stam Nicolis added a reply:

(1) Depends what is meant by ``super vacuum''. The words must, first, be defined, before questions can be asked. As it stands, it doesn't mean anything.

(2) To a good approximation the earth is moving around the Sun in a vacuum, i.e. its motion can be described by Newtonian mechanics, where the only bodies are the Earth and the Sun and the force between them is Newton's force of gravitation.

(3) Dark energy is the property of space and time that describes the fact that the Universe isn't, simply, expanding, but that this expansion is accelerating. To detect its effects it's necessary to measure the motion of bodies outside our galaxy.

To understand all this it's necessary to study classical mechanics-that leads to understanding the answer to the second question-and general relativity-in order to understand the answer to the third

László Attila Horváth added a reply:

Dear Abbas Kashani ,

The graviton - which creates or capture elementary X-rays and gamma rays- , by itself, it can be considered almost like a super vacuum.

Sergey Shevchenko added a reply:

What are rather numerous, and really strange, “vacuums” in mainstream physics, and what are two real vacuums is explained in the Shevchenko-Tokarevsky’s Planck scale informational physical model , 3 main papers are

https://www.researchgate.net/publication/367397025_The_Informational_Physical_Model_and_Fundamental_Problems_in_Physicssection 6. “Mediation of the fundamental forces in complex systems”

https://www.researchgate.net/publication/369357747_The_informational_model_-Nuclear_Force.

The first vacuum is the Matter’s fundamentally absolute, fundamentally flat, fundamentally continuous, and fundamentally “Cartesian”, (at least) [4+4+1]4D spacetime with metrics (at least) (cτ,X,Y,Z, g,w,e,s,ct), which is the actualization of the Logos set elements “Space” and “Time” [what are “Logos” set, “Space” and “Time” see first pages in 1-st or 2-nd links] at creation and existence of a concrete informational system “Matter”,

- i.e. this vacuum is a logical possibility for/of Matter’s existence and evolving, and so is by definition nothing else than some fundamentally “empty container” , i.e. is “real/absolute” vacuum.

The second vacuum, which can be indeed rationally called “physical vacuum”, is the Matter’s ultimate base – the (at least) [4+4+1]4D dense lattice of primary elementary logical structures – (at least) [4+4+1]4D binary reversible fundamental logical elements [FLE], which is placed in the Matter’s spacetime above;

- while all matter in Matter, i.e. all particles, fields, stars, galaxies, etc., are only disturbances in the lattice, that were/are created at impacts on some the lattice’s FLE. At that it looks as rather rational scientifically to assume, that such vacuum really existed – that was the initial version of the lattice that was created/formed at the “inflation epoch”, more see the SS&VT initial cosmological model in section “Cosmology” in 2-nd link.

After this initial lattice version was created, in the lattice a huge portion of energy was pumped uniformly globally [and non-uniformly locally], what resulted in Matter’s “matter” creation, which we observe now.

Since all disturbances always and constantly move in the lattice with 4D speeds of light, now can be only some “local physical vacuums”, etc.;

- though that is really quite inessential – the notion “physical vacuum” is completely useless and even wrong, since the really scientifically defined FLE lattice is completely enough at description n and analysis of everything that exists and happens in Matter. The introduced in mainstream physics “vacuums” really are nothing else than some transcendent/mystic/fantastic mental constructions that exist in mainstream physics because of in the mainstream all fundamental phenomena/notions, including “Matter”, “Space/space”, “Time/time” are fundamentally transcendent/uncertain/irrational,

- while these, and not only, really fundamental phenomena/notions can be, and are, really rigorously scientifically defined only in framework of the SS&VT philosophical 2007 “The Information as Absolute” conception, recent version of the basic paper see

- the SS&VT physical model is based on which.

More see the links above, a couple of SS posts in

https://www.researchgate.net/post/What_is_the_concept_of_quantized_vacuum_And_what_is_the_role_of_gravity_in_nature_And_what_is_the_relationship_between_dark_energy_and_quantum_gravi are relevant in this case also.

Abderrahman el Boukili added a reply:

Super vacuum, in my view, is just the vacuum itself, that is, the channel through which the universe of particles and anti-particles intersects.

Courtney Seligman added a reply:

For all practical purposes, the Earth is moving through a vacuum as it orbits the Sun, as there is so little of anything in any given place that only the most sensitive instruments could tell that there was anything there. But there are microscopic pieces of stuff that used to be inside asteroids or comets, and pieces of atoms blown out of the Sun as the Solar Wind, and cosmic rays that manage to get through the Sun's "heliosphere" and run into anything that happens to be in their way. So though the essentially empty space around the Earth would qualify as a vacuum by any historical standard, it isn't an absolutely perfect vacuum. And I suppose a "super vacuum" would be a region where there isn't anything at all, including not only matter, but also any form of energy (which has a mass equivalence of sorts, per Einstein's Special Theory of Relativity); and if so, then "super vacuums" do not exist.

Harri Shore added a reply:

The concepts you're exploring—super vacuum, dark energy, and the nature of the vacuum in quantum electrodynamics (QED) and quantum chromodynamics (QCD)—touch on some of the most profound and speculative areas in modern physics. Let's break down these concepts to provide clarity and context for your inquiry.

Super Vacuum

The term "super vacuum" is not widely used in mainstream physics literature but could be interpreted to mean an idealized vacuum state that is more "empty" than what is typically considered achievable, even beyond the vacuum state described by quantum field theories. In standard quantum field theories, a vacuum is not truly empty but seethes with virtual particles and fluctuates due to quantum uncertainties, known as zero-point energy.

Is the Earth in a Vacuum?

The Earth is not in a vacuum but is surrounded by its atmosphere, a thin layer of gases that envelops the planet. However, outer space, which begins just beyond the Earth's atmosphere, is often described as a vacuum. This is because outer space contains far fewer particles than the Earth's atmosphere, making it a near-vacuum by comparison. It's important to note that even the vacuum of outer space is not completely empty but contains low densities of particles, electromagnetic fields, and cosmic radiation.

Dark Energy

Dark energy is a hypothetical form of energy that permeates all of space and tends to accelerate the expansion of the universe. It is one of the greatest mysteries in modern cosmology, making up about 68% of the universe's total energy content according to current observations. The exact nature of dark energy is still unknown, but it is thought to be responsible for the observed acceleration in the expansion rate of the universe since its discovery in the late 1990s through observations of distant supernovae.

Vacuum Energy and Superluminosity

Vacuum energy refers to the energy that exists in space due to fluctuations of the quantum fields, even in the absence of any particles or radiation. It is a manifestation of the Heisenberg uncertainty principle in quantum mechanics, which allows for the temporary creation of particle-antiparticle pairs from "nothing."

The concept of superluminosity or superluminal phenomena (faster-than-light phenomena) is speculative and not supported by current mainstream physics, as it would violate the principle of causality, a cornerstone of the theory of relativity. However, there have been theoretical explorations of conditions under which apparent superluminal effects could occur without violating causality, such as in the context of quantum tunneling or warp drives in general relativity.

Vacuum Space as Evidence of Superluminous Energy

Your hypothesis suggests that vacuum space or "nothingness" might be evidence of a superluminous energy or vibration at the Planck scale that creates the apparent emptiness of space. This is a speculative notion that would require new theoretical frameworks beyond the standard model of particle physics and general relativity. It also implies that dark energy, the force behind the universe's accelerated expansion, could be related to this superluminous vacuum energy.

While current physical theories and experimental evidence do not support the existence of superluminous phenomena or energies, the history of science shows that our understanding of the universe is constantly evolving. Theoretical proposals that challenge existing paradigms are valuable for pushing the boundaries of our knowledge and prompting new avenues of experimental and theoretical investigation. However, any new theory that proposes mechanisms beyond established physics must be rigorously tested and validated against empirical evidence.

Courtney Seligman added a reply:

1. A vacuum is a region of space with no matter; a super vacuum could be defined in one of two ways, depending on whether it is a concept, or a description of current technology. In the first instance, it with be a region of space with neither matter nor energy (in which case, unless an extremely small region, it does not exist, because any part of space big enough to see without a microscope would at least have light of some sort passing through it (e.g., at least the Cosmic Background Radiation). In the second instance, it could be used to describe a "laboratory" vacuum which has far less matter in it than any previously created laboratory vacuum.

2. The Earth is in a region that is essentially a vacuum, because most of the space between the planets has practically nothing in it at any given time. However, there are cosmic rays and the Solar Wind everywhere, so though merely pieces of atoms, there is some stuff everywhere in space; but the amount is so small that for all "practical" purposes, it is a vacuum.

3. Dark energy is a fiction created by cosmologists to explain why, despite having too little mass for the gravity of that mass to fight the tendency of empty space to expand (per Einstein's General Theory of Gravity), the geometry of the Observable Universe is "flat", which would require something to add up to 100% of the "critical mass" of the Universe, and since visible and unobservable ("dark") matter makes up at most 27% of the critical mass, cosmologists created the concept of dark energy to make up the remaining 73%. However, there is no need to presume that the Universe is flat. Just as the Earth is a globe but looks essentially flat (on the average, and particularly at sea) because you can't see enough of it to see its real shape, the Universe is actually what is called "hyperbolic" in shape, which is exactly what you would expect if its mass is less than the "critical" mass. However, almost all cosmologists are convinced by various characteristics of the Observable Universe that the "real" Universe is at least 1000's and perhaps 10 to the 1000's of times bigger than what we can see, what we can see is too small to see its real shape, so it just looks "flat". Since by definition we can't see anything but the "Observable" Universe, we will never be able to see the true shape of the Universe; so "dark energy" will remain a "useful" fiction for calculation purposes for the foreseeable (if not infinite) future; but I am certain that we will never figure out what it is, because it doesn't exist. (Having been both a mathematician and a professional astronomer, I can assure you that even when something like "dark energy" doesn't exist in real life, creating a mathematical model that includes it, in order to make the math work right, is considered perfectly OK by professional mathematicians.)

Abbas Kashani added a reply:

Introduction The ‘Theory of Everything’ is a hypothetical theory of physics that explains and connects all known physical phenomena into one. There is a possible solution to the origin of gravity force, postulating it as angular piece of this theory, this solution erases gravity as one of the fundamental forces of nature and unifies it with strong nuclear force. Let’s analyze the forces that occur in the universe transforming string theory. It allows to explain many physical behaviors that without its existence would be practically impossible to understand, even so, these strings have not been able to be discovered and are only that, a theory that serves as an important support to the world of physics. One of the best known theoretical applications about them is how their vibration can provoke the creation of matter, but this is not about theories already written, we are going to place these strings in a simpler way to answer some doubts in subatomic world. This theory uses 4 dimensions in space and a behavior as one dimension in strings with superconducting capacities. Like an elastic band between V-shaped sticks where the elastic band slides down, the strong nuclear force, forces these strings to bend to fall dawn.

It’s not directly related to electromagnetism. . Actors . String Theory String theory is a theoretical framework in which the point-like particles of particle physics are replaced by onedimensional objects called strings. Each string that we cross would be the minimum distance that can be traversed during a displacement. We can note two important qualities of strings: Distance to the most distant object detected by the human being is more than 30 billion light years, that means there are beams of light which are able to travel that distance without decreasing its speed (they modify only its wavelength). Like light, an object can move into space for a practically unlimited period, as long as it doesn’t find a force to stop it. If strings exist, they act as a superconductor of matter with a resistance near 0. In order to generate waves it’s easier into a strongly linked structure. Gravitational waves behave like ocean waves which are similar to an uptight net, these tensions can be decomposed as one-dimensional structure for its study. Strings, at same time, could be one or zero-dimensional, like points under extreme bound forces, think about them as something tenser than any cable that holds the heaviest bridge in the world. The new framework we have drawn would be a set of extremely tense strings, with a practically infinite matter conduction capacity. Remember we are moving into universe at a stimated speed of 600km/sc. Strong Nuclear Force Strong nuclear force is another variable. This force allows the atomic nucleus to remain together, being the strongest of the so-called fundamental interactions (gravitational, electromagnetic, strong nuclear, and weak nuclear). Gluon is in charge of this interaction, it has a scope not greater than 10 to the power of -15 meters, preventing matter to separate by a constant attraction force between quarks of maximum 10.000 N (F). This real picture illustrates the three dimensional structure of gluon-field configurations, describing the vacuum properties. The volume of the box is 2,4 by 2,4 by 3,6 fm.Contrary to the concept of an empty vacuum, this induces chromo-electric and chromo-magnetic fields in its lowest energy state. The frame rate into this example is billions of billions frames per second (FPS). Superconducting String Theory (SST): Fundamentals: superconductor of matter interacting with a force that makes that matter hold together, but, how can they interact with each other? The most simple is to think about two V-shaped sticks (simulating the strings), and an elastic band that tight them at the most opened side (it would simulate the gluon, with size 10 to the power of -15 meters). If sticks are sufficiently lubricated and tense, what does the elastic band do? It will slide to the thinnest side. More elastic bands, more force will be exerted on the sticks to join them, so next bands will slide even faster (equally, more mass causes more attraction). We are talking about unknown limits in known world, such as infinite conduction or tensions never seen in materials. Suddenly, we have erased one of the fundamental forces of nature, gravity force doesn’t really exist, exists the strong nuclear force interacting with strings. this theory ‘Superconducting String Theory (SST)’. Calculations: Apply formulas from inclined planes (Newton’s second law). Simulation is in horizontal direction. Friction is imperceptible and acceleration down the plane is matched with gravity acceleration in our planet. Vertical force is not gravity force, it is gluon force, which values ares estimated, so we keep force 10.000 N (F1) and mass 0,0002 eV/c2 (m2). It can be considered vertical angle, but it’s depreciable.Dark energy and universe’s expansion. The behaviuor of the strings implies to have any kind of polaritation to expand, at least, strong enough to avoid get closer and restablish its structure after any contraction. This strength propagates over long distances.Gravitational constant (G = 6,67408 × 10−11 m3 kg-1s -2) and its problem to measure with high accuracy since it can be related to the density exposed. Schrödinger equation, to describe how the quantum state of a quantum system changes with time, similar to Newton's second law. Planck's length (1,616229 × 10-35 m) which can indicate the distance between strings. Gluon size and its larger size far from earth. Black holes.and .....

I only have a microinjector available to me Femtojet eppendorf ( I am new this and have never used the instrument). I would like to create a negative pressure and aspirate spores. The idea is not to load a needle for injection but merely selectively isolate spores from a mixed batch and aspirate them out and collect the spores at the end. Looking at the manual I can see that I cannot aspirate but maybe you creative people have any ideas/suggestions. I have a pump, I was thinking of attaching a syringe filled with cotton bud to reduce the suction or maybe I can use running water with a Y-joint tubing to create negative pressure, any ideas are welcome. Many Thanks Justina

Actually I am working at DSSC and QDSSC , I need to take EIS measurement of the cell/photoanode using Gammery instrument ,. Please suggest me to take the readings in Gammery instrument.

What could be a link between conformity to hegemonic masculinity and homophobia?

Hello connection

While performing potency test by using BD FACS instrument some time we few population inside the gate few outside of gate and some time I got population outside of the gate I am not able understand why it happened like I attached one picture please refer that one

Please provide valuable suggestions

Thank you in advance

Dear Forum Members,

I hope this message finds you well. I am currently considering the purchase of a Q-TOF LCMS-9030 Mass Spectrometer for my laboratory, and I would greatly appreciate hearing from anyone who has experience working with this instrument.

If you have used the Q-TOF LCMS-9030, I would be interested in hearing your thoughts and experiences. Specifically, I am seeking reviews on the instrument's performance, reliability, user-friendliness, and any limitations or challenges you may have encountered.

Your insights will be incredibly valuable in helping me make an informed decision about this purchase. Thank you in advance for sharing your expertise and feedback.

Best regards.

Dear all, 

After some months of procrastination, we changed 4/5 valves of our Accuri C6 (the ones that were not working), and I've started to check how the instrument is making measurements.

I have 2 issues for which I need help ;

- First, the instrument is unable to calibrate the fluidics. I thought the valve replacement would improve that point, but finally not. Do you have a hint  ?

- When I run the C6 with 0.2µm DI water, the recordings look like the attached picture. The threshold value is 80000 on the FSC-H channel. The event rate is close to 4000/s, and do not depend on the flow rate. 

Could you provide us any help ?

Thank you very much

Jacques FATTACCIOLI

UMR PASTEUR, Département de Chimie Ecole Normale Supérieure http://jacquesfattaccioli.wordpress.com https://microfluidics-master.fr Current address :  Institut Pierre-Gilles de Gennes 6 rue Jean Calvin 75005 Paris Tel/Fax : +33 1 40 79 58 92

I am not an expert in rheology and I have some questions.

I have two different brands of viscometers, a Thermo Electron Viscotester E-L and a Brookfield DV-II+Pro. I can not get the same result with the LV-4 spindle on the Thermo device with the spindle no 64 on the Brookfield device. Theoretically, I know that these two spindles are the same geometry. (Am I wrong?)

In the Brookfield device manual say" When viscosity data must be compared, be sure to use the same test methodology: namely the same instrument, spindle, speed, container, temperature and test time.". One of the results is 30k while the other is around 70k. However, I did not expect a big difference between the two devices. The only thing that comes to my mind is that "Brookfield dsoes not recommend the use of these spindles (LV #4) to perform a calibration check on your instrument. Reasons pertain to the small amount of spindle surface that makes contact with the viscosity standard, the difficulty of establishing the immersion mark precisely and the need for precise temperature control at 25°C in the immediate vicinity of the spindle." mentioned in the device manual.

How do I know which result is correct?

What are your thoughts on using Likert-type scales with another instrument that must total 100? Specifically, I'm curious about using 5-point or 7-point Likert scales in the same study with an instrument that offers a scale where the participant must total 100 with four dimensions. The Organizational Culture Assessment Instrument (OCAI) is the survey I am referring to. Can you pair that with typical Likert-type scales such as the Minnesota Satisfaction Questionnaire (MSQ) which is a 5-item Likert-type scale?

What kind of instrument do I need to measure the electrical conductivity of a very low conductive fluid such as mineral oil?

How to get the Pore Radius value from BJH data obtained using the BET instrument?

As I am confused I got BJH pore size distribution adsorption and desorption data. in which I got two different values of pore radius. which one should I use?

Please give suitable references too.

Thanks in Advance

Hi, can anyone assist me with the acceptable range for peak resolution. Literature states the Rs value should ideally be above 1.5.

From my DOE results I am obtained Rs values in the range 15 - 36 and that is very high, I have done manual calculations and I am still getting very high values >15.

The instrument I am using is Thermoscientific Ultimate 3000 HPLC and the software is Chromeleon 7.1.

I am using PCR Instrument called SLAN from HONGSHI. Any clue?

Hi, How do I look for instrument / tool related to leadership?

What is the wavelength of the X-ray radiation from an x-ray or CT Scan instrument in the medical field (used in hospitals or clinics)?

It is required to know the specific value, not just the range.

I have tried to contact the specific companies, but not get the suitable answers.

Thanks in advance.

Pittcon 2024, San Diego, CA, USA (Feb 24-28, 2024)

Time: Saturday, February 24, 2024, 8:30 AM to 5:00 PM (Full day course)

Short Course: SC-2561

Presenter: Dr. Nimal De Silva, Faculty Scientist, Geochemistry Laboratories, University of Ottawa, Ontario, Canada K1N 6N5

Email: [email protected]

Abstract:

Over the past few decades, instrumental analysis has come a long way in terms of sensitivity, efficiency, automation, and the use of sophisticated software for instrument control and data acquisition and processing. However, the full potential of such sophistication can only be realized with the user’s understanding of the fundamentals of method optimization, statistical concepts, calibration strategies and data processing, to tailor them to the specific analytical needs without blindly accepting what the instrument can provide. The objective of this course is to provide the necessary knowledge to strategically exploit the full potential of such capabilities and commonly available spreadsheet software. Topics to be covered include Analytical Statistics, Propagation of Errors, Signal Noise, Uncertainty and Dynamic Range, Linear and Non-linear Calibration, Weighted versus Un-Weighted Regression, Optimum Selection of Calibration Range and Standard Intervals, Gravimetric versus Volumetric Standards and their Preparation, Matrix effects, Signal Drift, Standard Addition, Internal Standards, Drift Correction, Matrix Matching, Selection from multiple responses, Use and Misuse of Dynamic Range, Evaluation and Visualization of Calibrations and Data from Large Data Sets of Multiple Analytes using EXCEL, etc. Although the demonstration data sets will be primarily selected from ICPES/MS and Chromatographic measurements, the concepts discussed will be applicable to any analytical technique, and scientific measurements in general.

Learning Objectives:

After this course, you will be familiar with:

- Statistical concepts, and errors relevant to analytical measurements and calibration.

- Pros and cons of different calibration strategies.

- Optimum selection of calibration type, standards, intervals, and accurate preparation of standards.

- Interferences, and various remedies.

- Efficient use of spreadsheets for post-processing of data, refining, evaluation, and validation.

Access to a personal laptop for the participants during the course would be helpful, although internet access during the course is not necessary. However, some sample- and work-out spreadsheets, and course material need to be distributed (emailed) to the participants day before the course.

Target Audience: Analytical Technicians, Chemists, Scientists, Laboratory Managers, Students

17th refers to the experimental parameter code

Material is mesoporous silica nanoparticles (MSN-NH2).

Use deionized water as dispersant and ultrasonic vibration.

The theoretical concentration is 9.6*10^(−5)g/ml.

The instrument used is zetasizer nano zs, the instrument is a bit old.

Hello experts and scholars, I would like to ask if I place a radar measuring instrument on a building to measure the vibration characteristics of a nearby building, how can I study the vibration of the instrument itself?

Which evaluation instruments are available for phonological awareness testing?

basically, we are conducting a electrocoagulation experiment and will be using this process to reduce nitrate to a certain level. However, we are struggling on what reagents to use since the nitrate checker from HANNA instruments is not an option since it can only detect from 0 to 75ppm. In the nitrate checker from HANNA instruments, they used malonic acid for their reagent but I'm not sure if its still useable at higher concentrations of 75ppm or do we use Griess reagent?

We had a comparison between the portable and stationary instruments related to particulate matter measuring.

The difference was significant about pm2.5.

Does anyone know what is the reason?

Hello everyone! Throughout my master's thesis and Ph.D. studies, I have encountered difficulties in achieving optimal clean-up of the UHPLC-ESI-MS/MS system.

My research focus lies in the analysis of peptides derived from plasma samples, and despite implementing an extensive pretreatment procedure aimed at eliminating proteins, particularly albumin, the chromatographic system consistently exhibits issues such as increased noise in the chromatogram and elevated column backpressure. Even the use of a pre-column has not provided a complete resolution to these challenges.

Notably, these problems seem to intensify when my colleagues, particularly those working in the metabolomic field, use the instrument following my experiments. Despite employing a thorough cleaning protocol involving a prolonged gradient elution (lasting approximately 1.5 hours) to ensure the removal of all potential samples residues from the system, the results remain the same.

I would like to know if you have come up with the same problems and if you ahve any insights on potential strategies to overcome these persistent issues. Whether it involves refining the pretreatment procedure, exploring alternative stationary phases, optimizing the cleaning protocol of the system, or considering additional precautions for shared instrument use.

Looking forward to hearing your experiences!

The project Knowledge in action for urban equality, KNOW ( www.urban-know.com.)has Havana as one of its City-Partners. The project looks for pathways towards urban equality.

One of the main research topics is related to the translation of knowledge about urban equality into planning instruments. We are looking for references.

How can one determine the stirring and sonication rate needed to get accurate and reliable results by a Mastersizer? We want to use this instrument to get a particle size distribution for a heterogeneous catalyst which we have synthesized.

How can I authenticate the measurements accuracy and precision of online downloaded software instrument.

Our hospital lab uses 5 biochemical auto analyser for patients samples analysis. Which quantity assurance protocol is best for the agreement of results of these instruments? Please examlify with number of samples, repeats and statistical tests analysis.

Most often our research labs might not have certain instruments that are necessary for the analysis of sample. Which research institute/Lab/educational institution provides best services for various research requirements such as sequencing, GCMS/LCMS, NMR, FTIR, HPLC-MS etc.

My instrument has 50 item from 6 IV and 1 DV, which is measured using likert scale. Prior to EFA, i need to remove outliers. what method should use? Univariate method or multivariate method?

What is the reason making the cyclic voltammograms looking so noisy like in the uploaded picture? is it a bad connection? something wrong with the instrument? or bad graphite source?

Rather than using a UV-Vis spectroscopy instrument, is it possible to develop a camera application that can perform the same work?

definition of statutory instruments and its effect on profitability of banking sector

I have obtained internal quantum efficiency from the instrument. But how can we calculate external quantum efficiency?

The topic is related to the use of artificial intelligence, namely the ChatGPT tool in the educational process in the open system, as well as in the open system in the financial field. What direct implications do you think will be in the field of education, finance and in the future of jobs.

the impacts of statutory instruments on banking perfomance

I am doing a chronopotentiometry study on a two electrode system using a CH instrument. I have only done studies on 3 electrode systems till now and connected the red cable to the counter electrode, white cable to the reference electrode and green one to the working electrode. when changing into two electrode system, to which electrode should I connect each of these cables?

I want to perform Photodetection studies of my bulk powder sample, but don't have any idea where to start. so it will be very helpful for me if someone who knows about this topic can give some suggestions.

I'm looking for a luxmeter to take measurements at night. I also want to calibrate other instruments using this certified luxmeter.

Thanks for your suggestions!

The CV plots of buffer solutions having PH 3-10 was done using CH instrument as well as using AutoLab. Both the results have different peak positions and different shapes.

I need a tool to measure the quality of care from nurses perception in accredited hospitals

I'm working on cultural identity, couldn't find the instrument or scale.

Anyone can guide me?

Dear researchers,

I am conducting a research on how eating behaviours and body dissatisfaction contribute to the stress level among undergraduate students in Malaysia for my Final Year Project. However, I need the Malay version of Eating Attitudes Test (EAT-26) as one of my instrument and I could not find it.

To anyone who has the Malay version, can you please send a copy to me or can you please tell me who should I contact?

Thank you very much.

Dear

I have PerkinElmer instrument. I am facing a Problem. I am not understanding how i can change unit from "mV to mAU" on software. so that my plot can appear mAU versus concentration. Can anyone guide me in this regard. My software is totalchromnavigator

I'm planning to run a single cell analysis experiment using the C1 Fluidigm Instrument. In my case, there is a limitation on the size of the cells that can be captured by the instrument 10-17um. I plan to use Calu-3 cells for my experiments. What is the average size of Calu-3 cells? Does it fit the criteria?

I am having trouble quantifying 6:2-Fluortelomersulfonsäure (6:2-FTS) using LCMSMSMS because of contamination. The sample is river water or ultrapure water, concentrated 1000x by solid phase extraction (Oasis® WAX; Waters, Milford, MA, US) and analyzed by LCMSMSMS (Xevo TQ-S micro (Waters)). The calibration range is 1~50 µg/L, but even ultrapure water may produce a chromatogram equivalent to several tens of µg/L of 6:2-FTS. Teflon is not used in the analysis. Glass instruments are cleaned with acetone and plastic instruments are cleaned with methanol before use. If anyone has faced a similar problem, I would like to know how to solve it. Thank you in advance.

Does strong correlation among the items in survey questionnaire, provides information on validity and reliability of that instrument?

For example. There are five items under a theme" happiness" for survey questionnaire. The item-total correlations for the five items were: 31, .63, .61, .75, and .66, thus, does it provides some information about reliability and validity of the items.

potentiodynamic polarization measurements for voltalab 100 is very noisy, how I can decrease this noise?

Please explain about the IRF (Instrument Response Function)? How it is measured and why it is important?

I am looking for a questionnaire that can be used to assess the sexual & reproductive health needs of students.

Thank you for your help.

I am a doctoral student needing to obtain permission to use the PSOC survey instrument to pass IRB. Any suggestions? The author is Charlotte Johnston in Canada.

Kimberlee K. Spicer

. xtabond2 IndicedeTheil PIBparhabitantUSconstants InflationdéflateurduPIBa ITC Créditintérieurfourniausecte, gmm( IndicedeThei

> l, lag(2 4)collapse) iv( PIBparhabitantUSconstants InflationdéflateurduPIBa ITC Créditintérieurfourniausecte) twostep small n

> odiffsargan

Favoring space over speed. To switch, type or click on mata: mata set matafavor speed, perm.

Dynamic panel-data estimation, two-step system GMM

------------------------------------------------------------------------------

Group variable: codepays Number of obs = 171

Time variable : Année Number of groups = 10

Number of instruments = 9 Obs per group: min = 12

F(4, 9) = 559.85 avg = 17.10

Prob > F = 0.000 max = 20

----------------------------------------------------------------------------------------------

IndicedeTheil | Coef. Std. Err. t P>|t| [95% Conf. Interval]

-----------------------------+----------------------------------------------------------------

PIBparhabitantUSconstants | .0000781 .0000141 5.53 0.000 .0000461 .00011

InflationdéflateurduPIBa | -.0137815 .0021388 -6.44 0.000 -.0186197 -.0089432

ITC | .0045328 .0029732 1.52 0.162 -.002193 .0112587

Créditintérieurfourniausecte | -.0241084 .0106227 -2.27 0.049 -.0481386 -.0000781

_cons | 3.522798 .8558666 4.12 0.003 1.586694 5.458903

----------------------------------------------------------------------------------------------

Warning: Uncorrected two-step standard errors are unreliable.

Instruments for first differences equation

Standard

D.(PIBparhabitantUSconstants InflationdéflateurduPIBa ITC

Créditintérieurfourniausecte)

GMM-type (missing=0, separate instruments for each period unless collapsed)

L(2/4).IndicedeTheil collapsed

Instruments for levels equation

Standard

PIBparhabitantUSconstants InflationdéflateurduPIBa ITC

Créditintérieurfourniausecte

_cons

GMM-type (missing=0, separate instruments for each period unless collapsed)

DL.IndicedeTheil collapsed

------------------------------------------------------------------------------

Arellano-Bond test for AR(1) in first differences: z = -0.35 Pr > z = 0.724

Arellano-Bond test for AR(2) in first differences: z = -0.68 Pr > z = 0.498

------------------------------------------------------------------------------

Sargan test of overid. restrictions: chi2(4) = 141.46 Prob > chi2 = 0.000

(Not robust, but not weakened by many instruments.)

Hansen test of overid. restrictions: chi2(4) = 5.04 Prob > chi2 = 0.283

(Robust, but weakened by many instruments.)

I have used a 5-point likert scale for my research on 'catalysing spiritual transformation'. The scale has 20 items divided equally across 4 domains (factors). It is a dual response scale and the first response rates the goal while the second response rates the accomplishment. It is a proven scale which has been validated for content and construct across continents. However, since I am using a translation for the first time, the author of the instrument who approved my translation, suggested that it is proper to do a fresh 'construct' validation for the translation. Accordingly I prepared to do CFA and found that my sample size after joining pretest and posttest data was only 174. I would like to join the two sets of responses of each questionnaire and double the sample size to 348, considering the fact that both sets of responses have identical structures though with different foci. I also noticed from the correlations matrices for the two sets of responses and the combination, that the correlation coefficients are significantly better for the combination and are all positive and > 0.5. Will it be scientifically sound to join the data of the two sets of responses and double my sample size as above?

Look forward to your valuable thoughts.

Thankfully

Lawrence F Vincent

Assuming I self-developed an instrument which I want to test its reliability and I am to select between these two, which of them will you recommend.

I am actually conscious of the "time interval" issue regarding the use of the former.

I am looking for a questionnaire that can be used to assess the sexual & reproductive health literacy of students.

Thank you for your help.

Hi, friends

I wrote two manuscripts regarding validations of two different instruments using a same sample.

Even though the two instruments are different, the demographic description is similar because they used same sample. In this case, it could be considered as plagiarism??

Is there anyone who wrote different manuscripts using a same sample?

I published one manuscript about A instrument. The other manuscript about B instrument is under review and one of reviewers pointed out that the manuscript had a risk of plagiarism.

In this case, what should I do??

Please give me a helpful tips.

Thank you so much.

I saw many examples, in classes, videos or tutorials, of creating a profile file of an XRD instrument, for Rietveld Refinement. But I did not understand how the standards are used to do this.

I know that the total peak broadening of a sample is the summation of the broadening related to this sample and the one related to the instrument, because the instrument itself provides some broadening, this is clear to me. That's why we measure the pattern from some standard, like LaB6 or Silicon-NIST, to determine how the broadening of the instrument is.

However, I don't see any tutorial or video taking into account the crystalite size and microstrain of these standars. Are they equal to 1, or something like it? I can't understand how they just refine the instrument parameters and "ignore" the characteristics of the standards.

Sincerely,

Ricardo Tadeu.

Most studies discuss clinical practice guideline development process, of which, the tool can be used to appraise clinical practice guidelines. However, I seem to not get quality assurance instruments for generic guidelines. Can one use same as with clinical practice guidelines? Example AGREE-HS or are there other tools to determine the quality of a well developed generic guideline (content, structure, flow, presentation) or are there recommended characteristics required for generic guideline development and appraisal?

I have design a polymeric hydrogel, done BET of that, degas that at 120 C for 16 hours but surface will become negative. Please help me out what should i do?

(Mention that there is no leakage of gas and instrument is calibrated)

Please assist by sharing articles that examined self image as variable, looking for existing instruments for my study.

I see that there are many screw-top tubes that are prefilled with glass beads, but these are usually used with bench-top homogenizers. I'm curious if it would work to use these tubes with a vortex instead of having to buy a new instrument. Has anyone tried this when homogenizing animal-tissue samples? If so, was the rest of your protocol successful?

FYI: We are interested in using this in a protocol for RNA extraction because our current workflow hasn't been giving us the best results.

I am currently conducting research on body image satisfaction and need to find appropriate instruments for measurement. I am looking for tools or questionnaires that specifically assess body image satisfaction among participants.

As I am still a final-year undergraduate student, I prefer to use instruments that are freely available and do not require any payment or subscription.

If anyone could suggest such instruments or questionnaires that have been used in previous research or are commonly available, I would greatly appreciate it.

Thank you in advance!

Top 500” Nigerian Authors for year 2020-2023 in Nigeria as captured by SciVal (An instrument used by the publishing giant, Elsevier and the Times Higher Education to rank World Class Universities).

Hello everyone,

I'm working on Wetland. I want to buy an instrument by which I can assess the physico-chemical parameters. Based on your experience please suggest which instrument is suitable for it.

About application of Bio-Rad iMark Microplate reader beyond immunoassays.

One of the instruments I am using in a study is official documents cotaining statistical data (figures, diagrams and charts); can this data be used in the qualitative phase of my study, knowing that the source is official documents, or it is quantitative in nature and should be used only in the quantitative phase?

What does it mean to say that a survey instrument has been validated . . . so what?

I need views and enlightenment from researchers about analyzing the data related to cross-cultural adaptation. What should I do to test the construct validity of an instrument which doesn't have a domain? Can I run the CFA, or only use item-total correlation to do a construct validity?

For additional information, the instrument has ten items with no domain.

Please kindly provide your suggestions related to this.

Thank you very much.

Dear All, I am trying to employ the CMP model to estimate recommended fertilizer dosage adoption's impact on ROI. The dataset contains seven years of balanced panel data. The endogenous variable is the Adoption decision (AdoptNot), and the instrumental variables for 'AdoptNot' are ‘FarmExp’ and ‘logOffFarmEarnTk.’ Following Dr. David Roodman's work, I have tried to construct the model as:    cmp (ROI = AdoptNot# IrriMachineOwn Seekinfofertilizer ACode EduC HHnumberCat HHLabor FarmExp LandSizeDec LandTypeC Landownership  SoilWaterRetain  CowdungAvailability  SoilFertility CreditAvail  BRRIKnowledge logOffFarmEarnTk year2015_d year2016_d year2017_d year2018_d year2019_d year2020_d year2021_d) ( AdoptNot =IrriMachineOwn Seekinfofertilizer ACode EduC HHnumberCat HHLabor FarmExp LandSizeDec LandTypeC Landownership  SoilWaterRetain  CowdungAvailability  SoilFertility EnviAwareness CreditAvail  BRRIKnowledge year2015_d year2016_d year2017_d year2018_d year2019_d year2020_d year2021_d logOffFarmEarnTk FarmExp), indicators ($cmp_cont $cmp_probit) But I am confused about the correct way of constructing this model. For instance, do I need to add the ROI variable in the second model too, and what is the correct order of placing instrumental variable/variables in the model?  Thank you very much in advance, and I look forward to hearing from you soon. Kind regards, Faruque

Is there any justification that states we can adapt items from more than 1 researcher in our measuring instruments.?

Dear all,

I have panel data with time invariant variable.

look at statistic for firststage the R Square Partial appear too low. There are any Threshold for Partial R Square...

Someone can help:

First-stage regression summary statistics

--------------------------------------------------------------------------

| Adjusted Partial

Variable | R-sq. R-sq. R-sq. F(2,746) Prob > F

-------------+------------------------------------------------------------

TURN_1 | 0.1417 0.1233 0.0713 28.6487 0.0000

--------------------------------------------------------------------------

Shea's partial R-squared

--------------------------------------------------

| Shea's Shea's

Variable | partial R-sq. adj. partial R-sq.

-------------+------------------------------------

TURN_1 | 0.0713 0.0527

--------------------------------------------------

Minimum eigenvalue statistic = 28.6487

Critical Values # of endogenous regressors: 1

H0: Instruments are weak # of excluded instruments: 2

---------------------------------------------------------------------

| 5% 10% 20% 30%

2SLS relative bias | (not available)

-----------------------------------+---------------------------------

| 10% 15% 20% 25%

2SLS size of nominal 5% Wald test | 19.93 11.59 8.75 7.25

LIML size of nominal 5% Wald test | 8.68 5.33 4.42 3.92

---------------------------------------------------------------------

estat overid

Tests of overidentifying restrictions:

Sargan (score) chi2(1) = 1.08549 (p = 0.2975)

Basmann chi2(1) = 1.06282 (p = 0.3026)

Best regards