Science

A 0.5-MHz antenna carried by an airplane flying over the ocean surface generates a wave that approaches the water surface in the form of a normally incident plane wave with an electricfield amplitude of 3,000 (V/m). Seawater is characterized by ?r = 72,

A 0.5-MHz antenna carried by an airplane flying over the ocean surface generates a wave thatapproaches the water surface in the form of a normally incident plane wave with an electricfieldamplitude of 3,000 (V/m). Seawater is characterized by ?r = 72, EXPERT ANSWER

If the ease of oxygen pick-up depends on oxygen concentration, would respiration be easier in air or in water?

EXPERT ANSWER Air consists of more free oxygen as compared to water (which consist of bound oxygen to water molecule). Also, in the air, the amount of oxygen is more as compared to water. Thus, if the oxygen pick-up would have depend upon the amount of oxygen, then the person would have been able to …

If the ease of oxygen pick-up depends on oxygen concentration, would respiration be easier in air or in water? Read More »

Pressure Drop in a Packed Bed Reactor The irreversible elementary gas phase reaction A + B → C + D is carried out in an isothermal packed bed reactor with 100 kg of catalyst of particle diameter DP1. Under the conditions of the reaction, the entering pressure into the reactor P0 was measured to be 20 atm and the outlet pressure was measured to be P = 2 atm. The flow of the gas inside the reactor is turbulent (neglect the laminar flow term in the Ergun Eqn.). If the catalyst particles inside the reactor are doubled in size so that DP2 = 2 DP1, what is the predicted outlet pressure if the weight of catalyst is unchanged?

EXPERT ANSWER

The elementary irreversible gas-phase reaction 2A à B + C is carried out isothermally in a PBR. Pure A enters the reactor at a volumetric flowrate of 20 dm3/s at a pressure of 10 atm and a temperature of 450 K. k is 15 dm6/mol.kg cat. sec.

Determine the volume of PBR necessary to achieve 85%. Given a is 0.019/kg.cat (10 Marks) What would be the conversion in the PBR if the mass flow rate decreased by a factor of 2 and particle size was doubled. (10 Marks) EXPERT ANSWER

the work and the heat per degree change of temperature for a system executing a non-flow process are given by dW/dt= 80 watt-sec/

EXPERT ANSWER dU = dQ – dW dQ = cal/C = 4.18 KJ/C ∴ dW = 80 watt -s /C = 80 J/C = 0.08 KJ/C ∴ dU/dt = 4.18 – 0.08 = 4.1 KJ/C ∴ dU = 4.1 .dT on integrating form T1 = (150 + 273) = 423 K to T2 = (250 …

the work and the heat per degree change of temperature for a system executing a non-flow process are given by dW/dt= 80 watt-sec/ Read More »

QUESTION 5. Below are two examples of colorectal cancer early lesions. Based on our discussion during the practical class, identify which image has the lesions with the HIGHER grade. Both cancers have genetic and genomic features typical of Consensus Molecular Subtype 1 (CMS1) of colorectal cancer. What are the genetic features of CSM1?

EXPERT ANSWER QUESTION 5 ANSWER: Image B has lesions with a higher grade. EXPLANATION: Image A shows low-grade lesions of colorectal carcinoma. Colon tumours that are poorly differentiated (high-grade) develop and spread more quickly than those that are well and moderately differentiated. HSIL aberrant squamous cells are darker and bigger than normal squamous cells when …

QUESTION 5. Below are two examples of colorectal cancer early lesions. Based on our discussion during the practical class, identify which image has the lesions with the HIGHER grade. Both cancers have genetic and genomic features typical of Consensus Molecular Subtype 1 (CMS1) of colorectal cancer. What are the genetic features of CSM1? Read More »

1. Beta-catenin is a core component of the cadherin protein complex, which plays a very crucial in the wnt-signaling pathway. In the absence of the wnt-signal, the Beta-catenin was mutated so that its phosphorylation is inhibited. What changes in the wnt-signaling pathway can be observed, under above conditions? What can be observed, if the TCF undergoes mutation causing it to be unable to bind to the transcription co-repressor (Groucho), in the absence of beta-catenin? Is beta-catenin capable of regulating the wnt gene expression process once TCF and the co-repressor (Groucho) are separated from the cell?

EXPERT ANSWER In animals, wnt family members are widely conserved since they are required during growth, tissue patterning, and homeostasis because the canonical wnt signaling pathway controls cell fate by regulating gene expression. This signaling pathway starts by binding to the Frizzled and LRP5/6 coreceptors leading to the formation of a nuclear transcription complex that …

1. Beta-catenin is a core component of the cadherin protein complex, which plays a very crucial in the wnt-signaling pathway. In the absence of the wnt-signal, the Beta-catenin was mutated so that its phosphorylation is inhibited. What changes in the wnt-signaling pathway can be observed, under above conditions? What can be observed, if the TCF undergoes mutation causing it to be unable to bind to the transcription co-repressor (Groucho), in the absence of beta-catenin? Is beta-catenin capable of regulating the wnt gene expression process once TCF and the co-repressor (Groucho) are separated from the cell? Read More »