increase rate
Recently Published Documents


TOTAL DOCUMENTS

320
(FIVE YEARS 125)

H-INDEX

18
(FIVE YEARS 4)

2022 ◽  
Vol 11 (1) ◽  
pp. 60
Author(s):  
Zhihuan Wang ◽  
Chenguang Meng ◽  
Mengyuan Yao ◽  
Christophe Claramunt

Maritime ports are critical logistics hubs that play an important role when preventing the transmission of COVID-19-imported infections from incoming international-going ships. This study introduces a data-driven method to dynamically model infection risks of international ports from imported COVID-19 cases. The approach is based on global Automatic Identification System (AIS) data and a spatio-temporal clustering algorithm that both automatically identifies ports and countries approached by ships and correlates them with country COVID-19 statistics and stopover dates. The infection risk of an individual ship is firstly modeled by considering the current number of COVID-19 cases of the approached countries, increase rate of the new cases, and ship capacity. The infection risk of a maritime port is mainly calculated as the aggregation of the risks of all of the ships stopovering at a specific date. This method is applied to track the risk of the imported COVID-19 of the main cruise ports worldwide. The results show that the proposed method dynamically estimates the risk level of the overseas imported COVID-19 of cruise ports and has the potential to provide valuable support to improve prevention measures and reduce the risk of imported COVID-19 cases in seaports.


Author(s):  
Danilo Coco ◽  
Silvana Leanza

Introduction: The diagnosis of abdominal pathologies in critically ill patients is often difficult because of inconclusive laboratory tests or imaging results, or the inability to safely transfer a patient to the radiology room. These causes give a delayed diagnosis of abdominal pathology in the intensive care unit (ICU) and increase rate of morbidity and mortality. The aim of this retrospective study is to evaluate the safety and diagnostic accuracy of bedside diagnostic laparoscopy in the identification of intra-abdominal pathology in critically ill patients. Aim: The aim of this retrospective study is to evaluate the safety and diagnostic accuracy of bedside diagnostic laparoscopy in the identification of intra-abdominal pathology in critically ill patients. Materials and Methods: A  literature research was carried out including PubMed, Medline, Embase, Cochrane and Google Scholar databases to identify articles reporting on importance of diagnostic accuracy of bedside diagnostic laparoscopy in the identification of intra-abdominal pathology in critically ill patients. Conclusions: Bedside diagnostic laparoscopy represents a safe and accurate technique for diagnosing intraabdominal pathology in an ICU setting and should be taken into consideration when patient transfer to radiology or the operating room is considered unsafe or when routine radiological examinations are not conclusive enough to reach a definite diagnosis. Keywords: Bedside laparoscopy, critically ill patients, ultrasonography (US), computed tomography (CT) , emergency surgery


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 561
Author(s):  
Changkyu Kim ◽  
Woong Kwon ◽  
Moon Hee Lee ◽  
Jong Seok Woo ◽  
Euigyung Jeong

This study aimed to investigate the effect of impregnation pressure on the decrease in porosity of impregnated bulk graphite. The correlation between pitch impregnation behavior and the pore sizes of the bulk graphite block was studied to determine the optimal impregnation pressure. The densities and porosities of the bulk graphite before and after pitch impregnation under various pressures between 10 and 50 bar were evaluated based on the Archimedes method and a mercury porosimeter. The density increased rates increased by 1.93–2.44%, whereas the impregnation rate calculated from the rate of open porosity decreased by 15.15–24.48%. The density increase rate and impregnation rate were significantly high when the impregnation pressures were 40 and 50 bar. Compared with impregnation pressures of 10, 20, and 30 bar, the minimum impregnatable pore sizes with impregnation pressures of 40 and 50 bar were 30–39 and 24–31 nm, respectively. The mercury intrusion porosimeter analysis results demonstrated that the pressure-sensitive pore sizes of the graphite blocks were in the range of 100–4500 nm. Furthermore, the ink-bottle-type pores in this range contributed predominantly to the effect of impregnation under pressure, given that the pitch-impregnated-into-ink-bottle-type pores were difficult to elute during carbonization.


2021 ◽  
Author(s):  
Yong Peng ◽  
fateh zereg ◽  
Anatoly Nikolaevich Tambovsky ◽  
Huan Zhu ◽  
Xiaoli Liu ◽  
...  

Abstract The objective of this study was to investigate the effects of square dance and brisk walking with the same frequency on the microvascular reactivity of the knee joint of elderly and middle-aged women. For the first time in Enshi city, women aged 55 to 65 years old were selected for experimental subjects, which included 15 in square dance group, 15 in Taijiquan group, 15 in fast walking group and 15 in control group. The changes in the skin microvascular reactivity of the knee joint were studied. The effects of various exercise regimens on the knee joint were evaluated. The results after the experiment, compared with the pre-experiment group, the increase rate of MBP in Taiji group increased significantly, but there was no significant change in square dance group, brisk walk group and control group (P > 0.05). The MBP in control group decreased in different degrees but not significantly (P > 0.05). The change in the AVBC rate in the Taijiquan group was significant, but not significantly so compared to the control group. The same results were obtained in the other groups. Hence, the increase rate of MBP in Taijiquan group was significantly higher than that in square dance group, fast walking group and control group, the increase rate of MBP in square dance group was significantly higher than that in control group, and the increase rate of AVBC in Taijiquan group was significantly higher than that in fast walking group and control group.


Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1103
Author(s):  
Tao Wang ◽  
Yan-Ling Ren ◽  
Tai-An Tian ◽  
Zhi-Tao Li ◽  
Xing-Ning Wang ◽  
...  

The cigarette beetle Lasioderma serricorne (Fabricius) is a major pest of stored products worldwide, especially tobacco and foods, causing huge economic losses. This study aimed to experimentally investigate the population dynamics of this pest at different temperatures and provide theoretical input for its control. Populations of L. serricorne were established under laboratory conditions at five temperatures (21 °C, 24 °C, 27 °C, 30 °C, and 33 °C). Results showed that an increasing temperature significantly affected the developmental time, longevity, oviposition period, and fecundity of L. serricorne. Both the longevity and fecundity of adult beetles were significantly reduced as the temperature increased. High temperatures significantly reduced the total duration of the preoviposition period but prolonged the oviposition period of L. serricorne. Increasing the temperatures from 21 °C to 33 °C significantly influenced the life table parameters of L. serricorne. The intrinsic increase rate (r), finite increase rate (λ), and gross reproductive rate (GRR) all increased with a greater rearing temperature, but mean generation time (T) was significantly shortened. To our best knowledge, this is the first report to detail the entire life history of the cigarette beetle in response to different temperatures when reared on tobacco dry leaves. This finding may provide basic information on the occurrence of L. serricorne in a warehouse setting and its mass rearing.


2021 ◽  
Author(s):  
Rohan D'Souza ◽  
Chigozie Emuchay ◽  
Paul Neil ◽  
Jeffery Clausen

Abstract Previously, few options existed for the complex directional challenges. Drillers either needed to rely on multiple Bottom Hole Assemblies (BHAs) or use expensive drive systems, which resulted in increased operational cost and limited drilling flexibility. This novel Downhole Adjustable Motor (hereafter referred to as downhole adjustable motor or the motor) described in the paper addresses these limitations by enabling the driller to change the motor bend in real-time downhole. In addition, the motor can deliver up to 1,000 horsepower (HP) at the bit during rotary drilling—the highest power in its size range. This paper will review how, even in harsh drilling applications, the downhole adjustable motor has proven to save trips, increase bit life, reduce lateral vibrations and stick-slip, and allow for drilling optimization to increase Rate of Penetration (ROP) and decrease overall drill time. Whether for drilling contracts or lump-sum turnkey projects, the directional drilling industry benefits from this new technology's ability to improve drilling economics while increasing safety by reducing drillpipe tripping and additional BHA handling.


2021 ◽  
pp. neurintsurg-2021-018187
Author(s):  
Zhipeng Li ◽  
Yu Chen ◽  
Pingting Chen ◽  
Ruinan Li ◽  
Li Ma ◽  
...  

BackgroundTo explore the hemodynamic changes after embolization of arteriovenous malformations (AVMs) using quantitative digital subtraction angiography (QDSA).MethodsWe reviewed 74 supratentorial AVMs that underwent endovascular embolization and performed a quantitative hemodynamic analysis comparing parameters in pre- and post-operative DSA in correlation with rupture. The AVMs were further divided into two subgroups based on the embolization degree: Group I: 0%–50%, Group II: 51%–100%. In the intergroup analysis, we examined the correlations between embolization degree and hemodynamic parameter changes.ResultsA longer time to peak (TTP) of the main feeding artery (OR 11.836; 95% CI 1.388 to 100.948; P=0.024) and shorter mean transit time (MTT) of the nidus (OR 0.174; 95% CI 0.039 to 0.766; P=0.021) were associated with AVM rupture. After embolization, all MTTs were significantly prolonged (P<0.05). The full width at half maximum (FWHM) duration of the main feeding artery was significantly shortened (P<0.001), and several hemodynamic parameters of the main draining vein changed significantly (TTP: prolonged, P=0.005; FWHM: prolonged, P=0.014; inflow gradient: decreased, P=0.004; outflow gradient: decreased, P=0.042). In the subgroup analysis, several MTT parameters were significantly prolonged in both groups (P<0.05), and the MTT increase rate in Group II was greater than in Group I (P<0.05).ConclusionsEmbolization can significantly change the hemodynamics of AVMs, especially when an embolization degree >50% is obtained. Partial embolization may reduce the AVM rupture risk in hemodynamics perspective.


2021 ◽  
Author(s):  
Ali Jebelli ◽  
Arezoo Mahabadi ◽  
Rafiq Ahmad

Abstract In most mines, methane gas is accumulated in pores inside coal, the highest amount of which is found in coal mines, and methane is the most important polluting gas in underground coal mines. In coal mining operations, coalbed methane is one of the potential hazards that must be extracted to prevent an explosion of the accumulated gas and environmental pollution. One of the mechanisms is using microwave irradiation so that the thermal stress caused by microwave heating generates fractures. In this research, we investigated the most important parameters affecting the electric and thermal fields’ distribution in coal in order to identify the effective parameters that achieve the highest temperature increase rate and to reach the highest impact and efficiency of the system with the least amount of consumed energy. The results of this study show that the most effective parameter on the electric and thermal fields’ distribution within coal is the size of the resonance chamber.


Author(s):  
Xijun Hua ◽  
Julius Caesar Puoza ◽  
Peiyun Zhang

Ultrasonic motors are typically driven by the dry friction force between the rotor and the stator; the friction pairs’ high friction coefficient and low wear rate are two essential elements for improving the operational stability with longer service life. In this research article, high-precision microgroove arrays were manufactured on the surfaces of the stator and rotor of the TRUSM60 ultrasonic motor using laser machining. Dry friction and wear tests between the stator and the rotor were carried out with pin-on-disc using HSR-2M high-speed reciprocating friction and wear tester to determine the tribological properties of the ultrasonic motor. According to a different distribution of microgrooves on the two contact surfaces, the influence of smooth surface, single-sided texture, and double-sided texture on the friction pair's friction performance were discussed. The results show that the textured surface can substantially increase the coefficient of friction of the contact surface and reduce the rate of wear. The one-sided textured phosphor bronze surface with a microgroove width of 200μm and an area ratio of 20% had the highest coefficient of friction of 0.334 and a friction increase rate of 36.3%. Similarly, the single-sided textured Polyimide surface attained the highest friction coefficient of 0.355 and friction increase rate of 44.9% when the groove width is 150μm and the area ratio is 30%. A higher friction coefficient of the double-sided texture can be obtained through reasonable parameter configuration than the single-sided texture. The included angle of 0° between the two textured surfaces produced the highest friction coefficient of 0.368 and the wear rate of the phosphor bronze and polyimide surfaces were 2.01 × 10−4 mm3/N-m and 1.949 × 10−3 mm3/N-m, respectively. The result provides an essential benchmark for enhancing the tribological performance of ultrasonic motors and increasing the output torque.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ammar Mansouri ◽  
Sabiha Keskas ◽  
Tarek Azli ◽  
Zohra Bouhila ◽  
Lylia Hamidatou ◽  
...  

Abstract In the present work, zinc levels were measured in scalp hair and fingernails in order to identify potential risk factors for breast cancer. The samples were collected from 40 Algerian breast cancer female patients and from 20 normal subjects matching the same age range. The concentration of zinc was analyzed using Instrumental neutron activation analysis technique (INAA). In scalp hair samples it was found in the range 119–792 μg/g for the normal subjects and in the range 82–806 μg/g for the patients, with an increase rate of 10.9%. The range of concentration of zinc in fingernails was found between 89 and 247 μg/g for normal subjects and between 75 and 276 μg/g for the patients with an increase rate of 2.5%. The influence of age on zinc concentration was also investigated. The obtained results show some consistency with those obtained by other groups.


Sign in / Sign up

Export Citation Format

Share Document