Cooling Load Calculations of Heat Gain for Buildings

Two recent papers [1,2] obtain formulas for temperature variations caused by the varying flow of solar heat through windows. These two works are used in the present study to develop a computer program for calculating the transient cooling load required to maintain the interior of a building at a given temperature. We assume that the building is standing by itself without surrounding radiating buildings or pavements. The heat gain through semi-transparent single or composite barriers is combined with the accompanying heat gain through the opaque walls; see Figure 1. The analytical solutions given in [1,2] cannot be represented directly as numerical terms in the cooling load. This is because the useful solutions in [1,2] exist as explicit solutions for the air temperature of the room; the solutions also exist in the form of a formal integral representation with the terms of the cooling load involved in the integrals. To obtain a solution of this part of the problem in numerical terms, two steps are involved: i. Numerical evaluations of the formal integral representation ii. Inversion of the indirect solutions to obtain the numerical results for the required cooling load. Two procedures can be followed to arrive at a· solution: One, we use the analytical solutions given in [1,2]; and two, we solve our problem directly from the differential formulation given in these references by numerical method. The mathematical representation of our problem was formulated into a computer program to perform the automatic calculations. This computer program is given in a separate volume available in the Department of Mechanical Engineering at South Dakota State University. Certain approximations are introduced in order to obtain the numerical results. The approximations associated with the numerical evaluations are discussed in Chapter III. The error induced due to the approximations can be reduced by using some of the more accurate approximation methods. However, the associated disadvantages in doing so are: 1. The flow chart for the automatic calculation system can be more complex in logic, and more difficult to understand. 2. The computer program associated with the flow chart can be more involved and larger in size to such an extent that it is not easily handled. Also, high accuracy can be attained by using smaller increments for each step of the calculations. But the required number of calculations will be greatly increased, and so will be the required computer time. For engineering applications, we prefer to have our methods simple and practical, so that they can be applied without difficulty by those who are interested

Transmission of methicillin-resistant staphylococcus aureus in the long term care facilities in Hong Kong

Background The relative contribution of long term care facilities (LTCFs) and hospitals in the transmission of methicillin-resistant Staphylococcus aureus (MRSA) is unknown. Methods Concurrent MRSA screening and spa type analysis was performed in LTCFs and their network hospitals to estimate the rate of MRSA acquisition among residents during their stay in LTCFs and hospitals, by colonization pressure and MRSA transmission calculations. Results In 40 LTCFs, 436 (21.6%) of 2020 residents were identified as ‘MRSA-positive’. The incidence of MRSA transmission per 1000-colonization-days among the residents during their stay in LTCFs and hospitals were 309 and 113 respectively, while the colonization pressure in LTCFs and hospitals were 210 and 185 per 1000-patient-days respectively. MRSA spa type t1081 was the most commonly isolated linage in both LTCF residents (76/121, 62.8%) and hospitalized patients (51/87, 58.6%), while type t4677 was significantly associated with LTCF residents (24/121, 19.8%) compared with hospitalized patients (3/87, 3.4%) (p < 0.001). This suggested continuous transmission of MRSA t4677 among LTCF residents. Also, an inverse linear relationship between MRSA prevalence in LTCFs and the average living area per LTCF resident was observed (Pearson correlation −0.443, p = 0.004), with the odds of patients acquiring MRSA reduced by a factor of 0.90 for each 10 square feet increase in living area. Conclusions Our data suggest that MRSA transmission was more serious in LTCFs than in hospitals. Infection control should be focused on LTCFs in order to reduce the burden of MRSA carriers in healthcare settings.published_or_final_versio

Non-Standard Errors

In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements