Perfect transfer of m-qubit GHZ states

By using some techniques such as spectral distribution and stratification associated with the graphs, employed in [1,2] for the purpose of Perfect state transfer (PST) of a single qubit over antipodes of distance-regular spin networks and PST of a $d$-level quantum state over antipodes of pseudo-distance regular networks, PST of an m-qubit GHZ state is investigated. To do so, we employ the particular distance-regular networks (called Johnson networks) J(2m,m) to transfer an m-qubit GHZ state initially prepared in an arbitrary node of the network (called the reference node) to the corresponding antipode, perfectly. Keywords: Perfect state transferenc, GHZ states, Johnson network, Stratification, Spectral distribution PACs Index: 01.55.+b, 02.10.YnComment: 17 page

A general algorithm for manipulating non-linear and linear entanglement witnesses by using exact convex optimization

A generic algorithm is developed to reduce the problem of obtaining linear and nonlinear entanglement witnesses of a given quantum system, to convex optimization problem. This approach is completely general and can be applied for the entanglement detection of any N-partite quantum system. For this purpose, a map from convex space of separable density matrices to a convex region called feasible region is defined, where by using exact convex optimization method, the linear entanglement witnesses can be obtained from polygonal shape feasible regions, while for curved shape feasible regions, envelope of the family of linear entanglement witnesses can be considered as nonlinear entanglement witnesses. This method proposes a new methodological framework within which most of previous EWs can be studied. To conclude and in order to demonstrate the capability of the proposed approach, besides providing some nonlinear witnesses for entanglement detection of density matrices in unextendible product bases, W-states, and GHZ with W-states, some further examples of three qubits systems and their classification and entanglement detection are included. Also it is explained how one can manipulate most of the non-decomposable linear and nonlinear three qubits entanglement witnesses appearing in some of the papers published by us and other authors, by the method proposed in this paper. Keywords: non-linear and linear entanglement witnesses, convex optimization. PACS number(s): 03.67.Mn, 03.65.UdComment: 37 page

Varicella Zoster antibodies among health care workers in a university hospital, Teheran, Iran

Objectives: This study was designed to evaluate the immune status of health care workers against varicella zoster in a university hospital in Teheran, Iran, and to compare the history of chickenpox infection with the presence of varicella antibodies in this population. Methods: Serologic testing for varicella was performed for 405 health care workers with different job categories and at different age. The enzyme immunoassay was used for determining IgG antibodies against varicella zoster virus Results: A total of 405 health care workers, aged 19-50 years (median: 29 years), were examined. Of these, 289 (71.4) were found to be seropositive. No statistically significant differences were observed between gender, age, or occupation, and seropositivity (p = 0.09, 0.75, 0.54. respectively). Statistical analysis revealed that the correlation between chickenpox history and seropositivity showed a 62.3 sensitivity, 72.4 specificity, 84.9 positive predictive value, and 43.5 negative predictive value. Conclusions: Serologic screening of health care workers is essential to determine their immunity to varicella, regardless of the age, occupation and history of infection. This population is recommended to be considered a target group for future immunization programs in Iran

Generating GHZ state in 2m-qubit spin network

We consider a pure 2m-qubit initial state to evolve under a particular quantum me- chanical spin Hamiltonian, which can be written in terms of the adjacency matrix of the Johnson network J(2m;m). Then, by using some techniques such as spectral dis- tribution and stratification associated with the graphs, employed in [1, 2], a maximally entangled GHZ state is generated between the antipodes of the network. In fact, an explicit formula is given for the suitable coupling strengths of the hamiltonian, so that a maximally entangled state can be generated between antipodes of the network. By using some known multipartite entanglement measures, the amount of the entanglement of the final evolved state is calculated, and finally two examples of four qubit and six qubit states are considered in details.Comment: 22 page

Effect of micro-aerobic process on improvement of anaerobic digestion sewage sludge treatment: Flow cytometry and ATP assessment

Micro-aeration as a pretreatment method improves the efficiency of anaerobic digestion of municipal sewage sludge and consequently promotes the methane production. In this study, adenosine triphosphate (ATP) and flow cytometry (FCM) were employed to monitor the performance of the micro-aerobic process and investigate the survival of bacterial cells within the process. At first, the effect of air flow rate (AFR) (0.1, 0.2, 0.3 and 0.5 vvm) on hydrolysis of mixed sludge in 5 aeration cycles (20, 30, 40, 48 and 60 hours) was examined. Then, the effects of the micro aerobic process on methane (CH4) production in anaerobic digestion were surveyed. The highest VSS reduction was 30.6 and 10.4 for 40 hours in the reactor and control, respectively. Soluble COD also fluctuated between 40.87 and 65.14 in micro-aerobic conditions; the highest SCOD was achieved at the time of 40 h. Microbial activities were increased by 597, 170 and 79.4 for 20, 30 and 40 h pretreatment with the micro-aerobic process, respectively. Apoptosis assay showed that micro-aerobic pre-treatment at 20, 30 and 40 h increased the percentage of living cells by 57.4, 62.8 and 67.9, respectively. On the other hand, FCM results showed that the highest percentage of viable bacteria (i.e., 67.9) was observed at 40 h pretreating which was approximately 40 higher the ones for the control. Variation in cumulative methane production shows that methane production was increased by 221 compared to anaerobic digestion (control group). Therefore, ATP and FCM can be employed as two appropriate, accurate, relatively specific indicators for monitoring the process and bacteria viability. © The Royal Society of Chemistry

The Prevalence of Nosocomial Infections in Iranian Hospitals

BACKGROUND AND OBJECTIVE: Nosocomial infections are one of the major health problems. As the length of stay in the hospital increases, the risk of mortality and morbidity increases, which ultimately increases the cost of treatment. Therefore, the present study was performed as a systematic review and meta-analysis to evaluate the prevalence of nosocomial infections in Iran. METHODS: This systematic review and meta-analysis was performed in the range of the years 2001 – 2017. Articles related to the topic were assessed using Persian keywords “nosocomial infections”, “hospital”, and “Iran”, and their English equivalent in descriptive and cross sectional studies by searching online databases of SID & Magiran, PubMed and Scopus, ScienceDirect and Google Scholar. Analytical and interventional studies were excluded from the study list. FINDINGS: 578 articles had the preliminary inclusion criteria, and with the removal of 568 unrelated or low quality articles during secondary analyses, 10 articles were finally included in the process of meta-analysis. The overall prevalence of nosocomial infections in Iranian hospitals was 4.6% (CI-95%: 2.6 – 8.1). The highest prevalence of nosocomial infections was in Sanandaj with 15.6% (CI-95%: 10.22–82.1) and the lowest prevalence was in Urmia with 0.4% (CI-95%: 0.1–1.01). CONCLUSION: The results of the study showed that nosocomial infection has a low prevalence in Iran, but more attention and control over nosocomial infections in Iranian hospitals is necessary to reach standard levels

The influence of combined low-strength ultrasonics and micro-aerobic pretreatment process on methane generation and sludge digestion: Lipase enzyme, microbial activation, and energy yield

Low-frequency ultrasonics is a potential technology to reduce the hydrolysis phase period in anaerobic digestion process. In this study, the influence of combined low frequency ultrasonics and micro-aerobic (MA) pretreatment on sewage sludge solubilization, enzyme activity and anaerobic digestion were assessed. Initially, the effect of ultrasonic density (0.012, 0.014, 0.016, 0.018, 0.1, 0.12 and 0.14 W/mL) and irradiation time (1, 3, 5, 8, 9, 10 and 12 min) of 20 kHz frequency waves were investigated. Accordingly, the effect of micro-aerobic pretreatment (Air flow rate (AFR) = 0.1, 0.2, 0.3 and 0.5 VVM) within 20, 30, 40.48 and 60 h were examined. In addition, the effect of combined pretreatment on COD solubilization, lipase enzyme activation, ATP, percentage of live bacteria and methane gas production during the anaerobic process were examined. The results showed that the highest lipase activity (14.9 Umol/mL) was obtained under the effect of ultrasonic density of 0.1 W/ml within 9 min. The highest solubilization (65) was observed under optimal micro-aerobic conditions: AFR = 0.2 (VVM) and micro-aerobic time: 40 h. Combined ultrasonic and micro-aerobic (US + MA) pretreatment increases the solubilization (70), microbial activity (2080) and lipase enzymatic activity (129) compared to individual pretreatment. The Biogas production during anaerobic digestion pretreated with combined methods increased by 193 compared to the control, while the elevated values of biogas production in reactors pretreated by ultrasonic and micro-aerobic pretreatment alone were observed to be 101 and 165, respectively. The net energy in reactor with the combined pre-treatment methods was calculated to be 1.26 kWh, while this value for control, pretreated ultrasonic and micro-aerobic reactors were obtained to be 0.56, 0.67 and 1.2 kWh, respectively. © 2021 The Author