Low Correlation Sequences over the QAM Constellation

This paper presents the first concerted look at low correlation sequence families over QAM constellations of size M^2=4^m and their potential applicability as spreading sequences in a CDMA setting. Five constructions are presented, and it is shown how such sequence families have the ability to transport a larger amount of data as well as enable variable-rate signalling on the reverse link. Canonical family CQ has period N, normalized maximum-correlation parameter theta_max bounded above by A sqrt(N), where 'A' ranges from 1.8 in the 16-QAM case to 3.0 for large M. In a CDMA setting, each user is enabled to transfer 2m bits of data per period of the spreading sequence which can be increased to 3m bits of data by halving the size of the sequence family. The technique used to construct CQ is easily extended to produce larger sequence families and an example is provided. Selected family SQ has a lower value of theta_max but permits only (m+1)-bit data modulation. The interleaved 16-QAM sequence family IQ has theta_max <= sqrt(2) sqrt(N) and supports 3-bit data modulation. The remaining two families are over a quadrature-PAM (Q-PAM) subset of size 2M of the M^2-QAM constellation. Family P has a lower value of theta_max in comparison with Family SQ, while still permitting (m+1)-bit data modulation. Interleaved family IP, over the 8-ary Q-PAM constellation, permits 3-bit data modulation and interestingly, achieves the Welch lower bound on theta_max.Comment: 21 pages, 3 figures. To appear in IEEE Transactions on Information Theory in February 200

Pultrusion of commingled thermoplastic composite materials

The work involves the analysis and verification of the pultrusion process. The pultrusion machine at UNLV was improved by modifying the consolidation and the cooling system. A comparative study of the material properties of the pultrusion process and the compression molding were done with the theoretical material properties. This involved a series of compression molding experiments of the commingled material followed by the pultrusion process itself. The results were then confirmed by a series of mechanical tests of the material obtained as a result of the pultrusion and the compression molding processes in the Material Test System (MTS) machine. The work also involved the setting up of a control system using LabView, instrumentation software. A data acquisition system and remote control system using serial communication was created for the pultrusion machine. The comparative study showed that compression molding samples were 32% stronger and had 52% higher modulus. All the data were plotted in a graph for better understanDing The changes in the consolidation did not improve the material properties but decreased the flexural strength by 60% and modulus by 75% from the previous dies. The material properties can be improved by changing the cooling system of the consolidation module. The flexural strength and the modulus of the pultrusion system were 10% and 15% better than the theoretically predicted values. The compression molding samples had flexural strength and the modulus were 20% better than the theoretically predicted

Calibration and application of a B-dot sensor to study the initiation of vacuum surface flashover

\u27Calibration\u27, as the name suggests is the act of checking or adjusting the accuracy of a measuring instrument by comparison with a standard. Two techniques, the equal length test and the short circuit test, have been developed to determine the characteristic impedance and propagation coefficient of a single lossy transmission line and a lossy transmission line network in cascade based solely on the input reflection coefficient S-parameter, S11, VNA measurements over a wide bandwidth of frequencies. For the transmission line network case, the characteristic impedance and propagation coefficient for each line in the cascade, excluding the last line, are known. Theoretical expressions needed for interpreting VNA measured data have been developed. A wideband, coaxial cable calibration test stand is characterized based on the novel equal length technique. The test stand is used to calibrate a B-dot in the frequency domain to obtain its response function. To verify the calibration process, the calibrated B-dot will be used to measure the surface current density on a radial transmission driven by a pulsed power source. These results will be compared against simulation using a Graphical Large Scale Plasma (GLSP) code. This calibrated B-dot will be used in future surface breakdown pulse power experiments on plastics measuring fast sub-nanosecond rise time phenomena

Implant Prophylaxis: The Next Best Practice Toward Asepsis in Spine Surgery.

Study designA literature review.ObjectivesAn evaluation of the contaminants prevalent on implants used for surgery and the aseptic methods being employed against them.MethodsPubMed was searched for articles published between 2000 and 2017 for studies evaluating the contaminants present on spine implants, and associated pre- and intraoperative implant processing and handling methodology suggested to avoid them. Systematic reviews, observational studies, bench-top studies, and expert opinions were included.ResultsEleven studies were identified whose major focus was the asepsis of implants to reduce the incidence of surgical site infection incidences during surgery. These studies measured the colony forming units of bacteria on sterilized implants and/or gloves from the surgeon, scrub nurse, and assistants, as well as reductions of surgical site infection rates in spine surgery due to changes in implant handling techniques. Additionally, the search included assessments of endotoxins and carbohydrates present on reprocessed implants. The suggested changes to surgical practice based on these studies included handling implants with only fresh gloves, keeping implants covered until the immediate time of use, reducing operating room traffic, avoiding reprocessing of implants (ie, providing terminally sterilized implants), and avoiding touching the implants altogether.ConclusionsBoth reprocessing (preoperative) and handling (intraoperative) of implants seem to lead to contamination of sterilized implants. Using a terminally sterilized device may mitigate reprocessing (preoperative implant prophylaxis), whereas the use of fresh gloves for handling each implant and/or a permanent shielding technique (intraoperative implant prophylaxis) could potentially avoid recontamination at the theatre

Report of Platythomisus octomaculatus (C. L. Koch, 1845) and Platythomisus sudeepi Biswas, 1977 from India (Araneae, Thomisidae)

The genus Platythomisus Doleschall, 1859 presently comprises 13 valid species, nine known from Africa and four from Asia. All Platythomisus species are known from females only, except P. jucundus Thorell, 1894 and P. sudeepi Biswas, 1977 from both sexes and P. quadrimaculatus from juvenile. Only, P. sudeepi was reported from India. Platythomisus octomaculatus (C. L. Koch, 1845) is recorded after 120 years of its last report; newly recorded from Assam, India which extends its distribution from the previously known localities, Java and Sumatra. Platythomisus sudeepi is newly recorded from the Maharashtra State. The variation in the number of abdominal spots on juvenile, sub-adult and adult of P. octomaculatus observed during rearing is reported. Although, the species name 'octomaculatus' suggests eight spots, we observed that the anterior pair of abdominal spots is fused in adults

A RETROSPECTIVE STUDY OF THE PREVALENCE OF DEPRESSION DUE TO LOW HAEMOGLOBIN COUNT

Objective: It has been shown that low haemoglobin count is associated with psychological consequences and psychiatric morbidity. The association between low haemoglobin count and psychological depression has not been properly interpreted with standard values. Hence the purpose of this pilot study is to know whether there is a relation between the haemoglobin levels and the risk of developing psychiatric disorders and morbidities. To find out if there is any relationship between low haemoglobin count and depression in a rural healthcare setup. Methods: Patients from the Psychiatry Department in Saveetha Medical College and Hospital were taken. Adults over the age of 18 were included. The period between the months September 2020 and July 2021. The primary outcome was the diagnosis of psychiatric depression and their associated blood haemoglobin values. Results: Among the other types of psychiatric disorders, the female patients with low haemoglobin count were associated with a significantly higher incidence of anxiety disorders, depression and adjustment disorders. Furthermore, patients with normal haemoglobin levels were associated with a significantly lower risk of psychiatric morbidities. Conclusion: The undergone study indicates that patients with psychiatric disorders such as depression, adjustment disorders and anxiety are related with significantly low haemoglobin counts in women and not in men

Right sided infective endocarditis: a forgotten complication of septic abortion

Right-sided native valve infective endocarditis (IE) refers to IE involving the tricuspid or pulmonic valve. In developing countries, septic abortion is still prevalent due to instrumental delivery by untrained personnel. We report a case of a 22-year-old lady with right-sided IE and pulmonary septic embolization complicating septic abortion. The patient was treated with IV antibiotics, however, she succumbed to the illness following worsening respiratory distress and cardiac arrest