Charge Equation For Small Charge Hydrocarbon Based Commercial Refrigeration Appliances

The use of hydrocarbon refrigerants has become common practice for small commercial appliances. The charge of hydrocarbon is limited by safety regulations. Therefore, refrigerant charge has become a critical design parameter for these appliances. To assist manufacturers in their early stage of appliance design (i.e. component selection) an easy to implement charge equation has been developed. The equation estimates the total appliance refrigerant charge based on the refrigerant, the operating conditions and the internal volume of the components of the cooling system. This paper presents the charge equation developed and discusses the derivation, assumptions and underlying calculations in detail. It is shown that the influence of refrigerant mass flux cannot be neglected. However, a simple approximation of the effect of mass flux is shown to be sufficient. The equation is validated based on the total refrigerant charge of 10 charge optimized glass door bottle coolers, varying in size from 50 to 1200 dm3, having a cooling capacity between 50 and 1500 W and using hydrocarbon as the refrigerant. The validation showed an agreement within 15% between the calculated and the actual refrigerant charge of the appliances

Optimisation Of Expansion Valve Control In Refrigeration Appliances Under Cyclic Operation

The result of an analytical and experimental study in developing a control strategy for expansion devices in small commercial refrigeration systems has been presented. The objective of the study was to improve system efficiency by optimization of the control of the expansion device. For this product type, typically capillary tubes are applied as the expansion device and compressor cycling is used to control product temperature. It is shown that for products with short operating periods (i.e. more than 4 cycles per hour), large energy saving potential exists by improvement of the evaporator filling during the first minutes after compressor activation and avoiding refrigerant migration during the compressor off cycle. A validated control strategy, based on the use of an electronic expansion device with closing valve functionality, is presented and the impact on cooling system design is discussed. Experimental validations using a dedicated test set-up, showed a reduction in cooling system energy consumption of 12 and 20% for respectively, a R-744 and a R-404A based cooling system of a vending machine in comparison to the benchmark capillary based system. Analyses showed that approximately 50-70% of this gain can be contributed to improving the cyclic average evaporator filling and that the remaining gain is resulting from avoiding refrigerant migration using closing valve functionality

Reducing Display Bottle Cooler Energy Consumption Using PCM As Active Thermal Storage

The final results of an analytical and experimental study in reducing the energy consumption of a display bottle cooler using Phase Change Material (PCM) as an active thermal storage are presented. The objective of the study was to design and built a 350 dm3 glass door bottle cooler having an appliance energy consumption reduction of over 75% compared to state of the art bottle coolers (2010 figures). Calculation results show that active thermal storage using PCM can be effectively applied to store and release cold on demand in small cooling appliances subjected to high peak loading. It is shown that by using the thermal storage much smaller cooling systems can be applied, resulting in system operation at reduced temperature lift. A validated control solution, including a sensor which detects the state of the PCM, is presented. It is shown that for a bottle cooler, optimum performance results for a dual forced air evaporator system, with one evaporator embedded in the PCM and the other in direct contact with the air stream. To obtain minimum product cooling times a different refrigerant flow path through the evaporators is required between the main modes of operation (i.e. peak loading or recovery). The optimum position of the PCM embedded evaporator is upstream of the main evaporator with respect to the airflow. A design of a display bottle cooler applying standard heat load reduction measures in combination with PCM as active thermal storage is presented. The design is based on using a 5.19 cm3 R-600a compressor in combination with forced air heat exchangers. The integration of the PCM in the appliance cooling system and the control aspects resulting are discussed in detail. Experimental test results of a demonstrator cabinet at an ambient of 25 °C and 60 %RH show that a 350 dm3 glass door bottle cooler having a total appliance energy consumption (including half reload recovery) of \u3c 1 kWh/24 h can be built while achieving a half reload recovery within 16 h at an ambient of 32 °C and 65 %RH

De “ultieme HRM-vraag”: Zou jij je werkgever aanbevelen aan familie en vrienden?

Organisaties streven daarom naar 'loyale' werknemers. Er zijn al verschillende manieren om loyaliteit te meten, zoals via 'organisatiebetrokkenheid'. Maar is er niet één ultieme vraag die we kunnen stellen? Misschien kunnen we deze loyaliteit meten via de zogenaamde 'Werkgever Net Promotor Score'. Deze vraag is afgeleid van het artikel van Frederick Reichfeld uit de Harvard Business Review, getiteld "The one number you need to grow". Reichfeld stelt er een 'ultieme vraag' is die bedrijven aan hun klanten kunnen stellen. Deze vraag: "In welke mate beveelt u deze organisatie aan bij vrienden en familie?" wordt in klanttevredenheidsonderzoeken gebruikt gebruikt om de loyaliteit van klanten te meten

Cardiac involvement in adults with Pompe disease

Background. Glycogen storage disease type II or Pompe disease is a neuromuscular disorder caused by deficiency of lysosomal acid α- glucosidase. Classic infantile Pompe disease results in massive left ventricular (LV) hypertrophy and failure. Although Pompe disease is often included in the differential diagnosis of LV hypertrophy the true frequency of cardiac involvement in adults with Pompe disease is not known. Methods. Forty-six consecutive adult patients (mean age 48 ± 12, 22 men) with Pompe disease were included. Each patient underwent a clinical examination, electrocardiography, and rest and low-dose dobutamine (in 20 patients) two-dimensional echocardiography including contrast and tissue Doppler imaging. Results. All patients had limited exercise tolerance; a rollator walking aid was used in seven patients (15%), a wheelchair in 13 patients (28%), and assisted ventilation in 14 patients (30%). Prior to this study, one patient was known with permanent atrial fibrillation, His-bundle ablation and a VVI pacemaker and another patient was known with fluid retention. The first patient had increased LV end-diastolic diameter, impaired LV ejection fraction, low systolic mitral annular velocities and diastolic dysfunction grade II. The patient with fluid retention was wheelchair bound and dependent on 24-h assisted ventilation and showed right ventricular and LV hypertrophy (septum 16 mm, posterior wall 15 mm). LV hypertrophy was not seen in any of the other patients. One woman of advanced age had isolated low systolic mitral annular velocities. Mean global systolic LV function, including contractile reserve, was not decreased in patients with Pompe disease. Eight patients (17%) had mild diastolic dysfunction grade I, related to hypertension in four and advanced age in seven. Conclusions. In adult patients with Pompe disease without objective signs of cardiac affection by 12-leads electrocardiography or physical examination, echocardiographic screening for LV hypertrophy seems not effective

Oseltamivir-resistant influenza A(H1N1)pdm09 virus in Dutch travellers returning from Spain, August 2012

Two Dutch travellers were infected with oseltamivirresistant influenza A(H1N1)pdm09 viruses with an H275Y neuraminidase substitution in early August 2012. Both cases were probably infected during separate holidays at the Catalonian coast (Spain). No epidemiological connection between the two cases was found, and neither of them was treated with oseltamivir before specimen collection. Genetic analysis of the neuraminidase gene revealed the presence of previously described permissive mutations that may increase the likelihood of such strains emerging and spreading widely

Influenza A(H1N1) Oseltamivir Resistant Viruses in the Netherlands During the Winter 2007/2008

Background: Antiviral susceptibility surveillance in the Netherlands was intensified after the first reports about the emergence of influenza A(H1N1) oseltamivir resistant viruses in Norway in January, 2008. Methods: Within the existing influenza surveillance an additional questionnaire study was performed to retrospectively assess possible risk factors and establish clinical outcome of all patients with influenza virus A(H1N1) positive specimens. To discriminate resistant and sensitive viruses, fifty percent inhibitory concentrations for the neuramidase inhibitors oseltamivir and zanamivir were determined in a neuraminidase inhibition assay. Mutations previously associated with resistance to neuramidase inhibitors and M2 blockers (amantadine and rimantadine) were searched for by nucleotide sequencing of neuraminidase and M2 genes respectively. Results: Among 171 patients infected with A(H1N1) viruses an overall prevalence of oseltamivi resistance of 27% (95% CI: 20-34%) was found. None of influenza A(H1N1) oseltamivir resistant viruses tested was resistant against amantadine or zanamivir. Patient characteristics, underlying conditions, influenza vaccination, symptoms, complications, and exposure to oseltamivir and other antivirals did not differ significantly between patients infected with resistant and sensitive A(H1N1) viruses. Conclusion: In 2007/2008 a large proportion of influenza A(H1N1) viruses resistant to oseltamivir was detected. There were no clinical differences between patients infected with resistant and sensitive A(H1N1) viruses. Continuous monitoring of the antiviral drug sensitivity profile of influenza viruses is justified, preferably using the existing sentinel surveillance, however, complemented with data from the more severe end of the clinical spectrum. In order to act timely on emergencies of public health importance we suggest setting up a surveillance system that can guarantee rapid access to the latter. (aut. ref.

Integrative analysis of genomic amplification-dependent expression and loss-of-function screen identifies ASAP1 as a driver gene in triple-negative breast cancer progression

The genetically heterogeneous triple-negative breast cancer (TNBC) continues to be an intractable disease, due to lack of effective targeted therapies. Gene amplification is a major event in tumorigenesis. Genes with amplification-dependent expression are being explored as therapeutic targets for cancer treatment. In this study, we have applied Analytical Multi-scale Identification of Recurring Events analysis and transcript quantification in the TNBC genome across 222 TNBC tumors and identified 138 candidate genes with positive correlation in copy number gain (CNG) and gene expression. siRNA-based loss-of-function screen of the candidate genes has validated EGFR, MYC, ASAP1, IRF2BP2, and CCT5 genes as drivers promoting proliferation in different TNBC cells. MYC, ASAP1, IRF2BP2, and CCT5 display frequent CNG and concurrent expression over 2173 breast cancer tumors (cBioPortal dataset). More frequently are MYC and ASAP1 amplified in TNBC tumors (>30%, n = 320). In particular, high expression of ASAP1, the ADP-ribosylation factor GTPase-activating protein, is significantly related to poor metastatic relapse-free survival of TNBC patients (n = 257, bc-GenExMiner). Furthermore, we have revealed that silencing of ASAP1 modulates numerous cytokine and apoptosis signaling components, such as IL1B, TRAF1, AIFM2, and MAP3K11 that are clinically relevant to survival outcomes of TNBC patients. ASAP1 has been reported to promote invasion and metastasis in various cancer cells. Our findings that ASAP1 is an amplification-dependent TNBC driver gene promoting TNBC cell proliferation, functioning upstream apoptosis components, and correlating to clinical outcomes of TNBC patients, support ASAP1 as a potential actionable target for TNBC treatment

Update of the Preventive Antibiotics in Stroke Study (PASS): Statistical analysis plan

Background: Infections occur in 30% of stroke patients and are associated with unfavorable outcomes. Preventive antibiotic therapy lowers the infection rate after stroke, but the effect of preventive antibiotic treatment on functional outcome in patients with stroke is unknown. The PASS is a multicenter, prospective, phase three, randomized, open-label, blinded end-point (PROBE) trial of preventive antibiotic therapy in acute stroke. Patients are randomly assigned to either ceftriaxone at a dose of 2 g, given every 24 h intravenously for 4 days, in addition to standard stroke-unit care, or standard stroke-unit care without preventive antibiotic therapy. The aim of this study is to assess whether preventive antibiotic treatment improves functional outcome at 3 months by preventing infections. This paper presents in detail the statistical analysis plan (SAP) of the Preventive Antibiotics in Stroke Study (PASS) and was submitted while the investigators were st

A Restricted Role for FcγR in the Regulation of Adaptive Immunity.

By their interaction with IgG immune complexes, FcγR and complement link innate and adaptive immunity, showing functional redundancy. In complement-deficient mice, IgG downstream effector functions are often impaired, as well as adaptive immunity. Based on a variety of model systems using FcγR-knockout mice, it has been concluded that FcγRs are also key regulators of innate and adaptive immunity; however, several of the model systems underpinning these conclusions suffer from flawed experimental design. To address this issue, we generated a novel mouse model deficient for all FcγRs (FcγRI/II/III/IV-/- mice). These mice displayed normal development and lymphoid and myeloid ontogeny. Although IgG effector pathways were impaired, adaptive immune responses to a variety of challenges, including bacterial infection and IgG immune complexes, were not. Like FcγRIIb-deficient mice, FcγRI/II/III/IV-/- mice developed higher Ab titers but no autoantibodies. These observations indicate a redundant role for activating FcγRs in the modulation of the adaptive immune response in vivo. We conclude that FcγRs are downstream IgG effector molecules with a restricted role in the ontogeny and maintenance of the immune system, as well as the regulation of adaptive immunity