Singularities and the Finale of Black Hole Evaporation

In this essay we argue that once quantum gravitational effects change the classical geometry of a black hole and remove the curvature singularity, the black hole would not evaporate entirely but approach a remnant. In a modified Schwarzschild spacetime characterized by a finite Kretschmann scalar, a minimal mass of the black hole is naturally bounded by the existence of the horizon rather than introduced by hand. A thermodynamical analysis discloses that the temperature, heat capacity and the luminosity are vanishing naturally when the black hole mass approaches the minimal value. This phenomenon may be attributed to the existence of the minimal length in quantum gravity. It can also be understood heuristically by connecting the generalized uncertainty principle with the running of Newton's gravitational constant.Comment: 10 page

Recovery of Palm Carotene from Palm Oil and Hydrolysed Palm Oil Using Adsorption Column Chromatography

Crude palm oil (CPO) and crude palm olein (CPOlein) were hydrolysed with lipase from Candida Rugosa to produce free fatty acids (FFAs)- rich oil. The palm oil and hydrolysed palm oil were subsequently subjected to column chromatography process. Diaion HP-20 adsorbent was used for reverse phase column chromatography and the column temperature was kept at 50°C. Isopropanol (IPA) or ethanol (EtOH), and n-hexane were used as the first and second eluting solvents, respectively. The objective of hydrolysing the palm oil was to produce more polar FFA-rich oil in order to enhance the non-polar carotene to adsorb to the non-polar HP-20 adsorbent in the column chromatography. The results obtained showed that by hydrolysing CPO and CPOlein with lipase from Candida rugosa, gave 30- and 60-fold, respectively, of FFA production in the crude palm oil and crude palm olein in 8 h at 50°C. For column chromatographic process, using isopropanol or ethanol as the first eluting solvent, crude oil and hydrolysed oil showed the carotene recovery in fraction two (carotene-rich fraction) were about 36-37 and 90-96%, respectively. Over 90% of carotene recovery was obtained from hydrolysed palm oil reflecting an increase of about 55% over CPO. Response Surface Methodology (RSM) for optimisation of carotene recovery from hydrolysed palm olein (HCPOlein) in adsorption chromatography was carried out. The level and interaction of three independent variables was investigated: column temperature (50 to 60°C), oil loading (25 to 200 g), and mobile phase flow rate (6 to 60 mL/min) was investigated. Based on the response as percentage of carotene recovery from 50 g of HP-20 adsorbent, the optimum conditions were achieved at 200 g of oil loading, column temperature at 55°C, and flow rate at 33 mL/min. Up to 98% of carotene recovery was able to obtain under this condition. Interaction of oil-oil and oil-flow rate could enhance percentage of carotene recovery. On the other hand, oil and flow rate as single factors could significantly reduce percentage of carotene recovery. Oil loading as a single factor could positively influence amount of carotene adsorbed. However, flow rate as a single factor and oil-oil interaction could negatively influence amount of carotene adsorbed. The predicted results according to the model for both responses were closed to the observed responses for experiments. The mean of difference (MD) of the experimental and predicted data for percentage of carotene recovery, and amount of carotene adsorbed were very small, - 0.0067 and 0.0133, respectively. The probability (P) value showed no significant lackof- fit for both equations of this model. Laboratory-scale batch studies were carried out to investigate the use of synthetic polymer adsorbent, HP-20, for carotene extraction from CPOlein and HCPOlein. The adsorption of carotene was determined by several adsorption isotherm models such as Langmuir, Freundlich and Scatchard plots. The effect of temperature, contact time, adsobate concentration and the adsorbent mass were examined. The equilibrium data fitted with both Langmuir and Freundlich models with correlation coefficients >0.9.e concentration and the adsorbent mass wer

Outcomes and expenditures of clostridium difficile infection in pediatric solid organ transplant recipients

textThe main purpose of this study was to assess outcomes (i.e., inpatient mortality, transplant failure or rejection, colectomy, and hospital length of stay) of clostridium difficile infection (CDI) and the association of expenditures (i.e., charges and costs) and CDI in pediatric solid organ transplant (SOT) recipients. Data from the 2000, 2003, 2006, and 2009 Kids’ Inpatient Database (KID) files were used to identify events with SOT- related ICD-9-CM diagnosis codes. Logistic regression was used to assess the association of CDI and dichotomous outcome variables, while log-linked gamma regression models were used to assess the association of CDI and continuous outcome variables. Methods accounting for the complex survey sample design of the KID were used when performing all statistical analyses. The total number of pediatric SOT hospital events was 48,286. The overall prevalence of CDI for pediatric SOT hospitalizations was 1.76%. For SOT hospitalizations with CDI, inpatient mortality was 1.63%; the prevalence of transplant failure or rejection events was 27.71%; the prevalence of a colectomy was 4.86%. The median hospital length of stay was seven days; the median charge and cost for each hospitalization was $48,409 and$17,412, respectively. The results showed that CDI was not significantly associated with inpatient mortality or transplant failure/ rejection in pediatric SOT hospitalizations. SOT patients with CDI were 2.6 times more likely to have a colectomy than SOT patient without CDI. The mean hospital length of stay (LOS) for a SOT admission with CDI was approximately 2 times the mean LOS for a SOT admission without CDI. The mean charges and the mean costs for a SOT admission with CDI was approximately 2 times that for a SOT admission without CDI. In conclusion, CDI diagnoses were not significantly associated with higher inpatient mortality or transplant failure/ rejection for pediatric SOT hospitalizations. But CDI was significantly associated with a higher prevalence of a colectomy, longer hospital LOS, higher charges, and higher costs (all p<0.05). To avoid substantially higher expenditures and health care utilization, CDI in pediatric SOT recipients should be prevented when possible and promptly diagnosed and treated when it occurs.Pharmaceutical Science

Variable-frequency-controlled coupling in charge qubit circuits: Effects of microwave field on qubit-state readout

To implement quantum information processing, microwave fields are often used to manipulate superconuducting qubits. We study how the coupling between superconducting charge qubits can be controlled by variable-frequency magnetic fields. We also study the effects of the microwave fields on the readout of the charge-qubit states. The measurement of the charge-qubit states can be used to demonstrate the statistical properties of photons.Comment: 7 pages, 3 figure