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2022 ◽  
Vol 141 ◽  
pp. 104530
Author(s):  
Mingchun Lin ◽  
Wei Zhou ◽  
Jiaying Liu ◽  
Gang Ma ◽  
Xuexing Cao

2022 ◽  
Vol 354 ◽  
pp. 00003
Author(s):  
Daniel Nicu Fraitag ◽  
Mihai Popescu-Stelea ◽  
Roland Iosif Moraru ◽  
Gabriel Bujor Băbuţ

Only an objective knowledge of safety and health at work reality on the harbor platform and an active participation of all stakeholders (employers, unions, workers) can bring an improvement in this activity. The prevention of accidents at work by ensuring safe and healthy working conditions and maintaining the Occupational Safety and Health Management system are factors that continuously develop and improve safety performance by helping to actively manage risks. This paper aims to systematize the information available, both at European and national level so as to develop a strategy at the organizational level that can be included in a guide to optimal safety and health practices for harbor operations. The paper also proposes relevant practical aspects of safety and health at work in the activities carried out in the loading and unloading flow in / from the port of the ship, trying to support the knowledge and understanding of identification, assessment and prevention of specific risks.


Genes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 72
Author(s):  
Shaopeng Pei ◽  
Shubo Wang ◽  
Jerahme R. Martinez ◽  
Ashutosh Parajuli ◽  
Catherine B. Kirn-Safran ◽  
...  

The proteoglycan-containing pericellular matrix (PCM) controls both the biophysical and biochemical microenvironment of osteocytes, which are the most abundant cells embedded and dispersed in bones. As a molecular sieve, osteocytic PCMs not only regulate mass transport to and from osteocytes but also act as sensors of external mechanical environments. The turnover of osteocytic PCM remains largely unknown due to technical challenges. Here, we report a novel imaging technique based on metabolic labeling and “click-chemistry,” which labels de novo PCM as “halos” surrounding osteocytes in vitro and in vivo. We then tested the method and showed different labeling patterns in young vs. old bones. Further “pulse-chase” experiments revealed dramatic difference in the “half-life” of PCM of cultured osteocytes (~70 h) and that of osteocytes in vivo (~75 d). When mice were subjected to either 3-week hindlimb unloading or 7-week tibial loading (5.1 N, 4 Hz, 3 d/week), PCM half-life was shortened (~20 d) and degradation accelerated. Matrix metallopeptidase MMP-14 was elevated in mechanically loaded osteocytes, which may contribute to PCM degradation. This study provides a detailed procedure that enables semi-quantitative study of the osteocytic PCM remodeling in vivo and in vitro.


2021 ◽  
Vol 9 ◽  
Author(s):  
Hang Yu ◽  
Xue-mei Shen ◽  
Yu-chen Ye ◽  
Jie Yang ◽  
Chen-hui Zhu

The dilatancy equation, which describes the plastic strain increment ratio and its dependence on the stress state, is an important component of the elastoplastic constitutive model of geotechnical materials. In order to reveal their differences of the dilatancy value determined by the total volume strain increment ratio and the real value of lean cemented sand and gravel (LCSG) materials, in this study, a series of triaxial compression tests, equiaxial loading and unloading tests, and triaxial loading and unloading tests are conducted under different cement contents and confining pressures. The results reveal that hysteretic loops appear in the stress–strain curves of equiaxial loading and unloading tests, and triaxial loading and unloading tests and that the elastic strain is an important component of the total strain. The hysteretic loop size increases with an increase in the stress level or consolidation stress, whereas the shape remains unchanged. Furthermore, with an increase in the cement content, the dilatancy value determined by the total volume strain increment ratio becomes smaller than that determined by the plastic strain increment ratio, and the influence of the elastic deformation cannot be ignored. Thus, in practical engineering scenarios, especially in the calculation of LCSG dam structures, the dilatancy equation of LCSG materials should be expressed by the plastic strain increment ratio, rather than the total volume strain increment rati.


2021 ◽  
Vol 1 (2) ◽  
pp. 74-83
Author(s):  
Abiyani Choirul Huda ◽  
Rendatiyarso Laksono ◽  
Anggie V R Dewi ◽  
Rima G Harahap ◽  
Nurwati Nurwati ◽  
...  

Dock C is one of the supporting facilities at PT. Petrokimia Gresik which functions as loading and unloading goods from ships to land and vice versa. Another benefit of the jetty is that it can significantly increase the company's production capacity. Dock C PT. Petrokimia Gresik. In the treatment of sedimentation in port it is necessary to analyze the current pattern and sedimentation rate early, because this is the first step to predict the amount of sedimentation contained in the port in a certain period of time. Several ways can be done to minimize the rate of sedimentation, one of which is the layout of Dock C to reduce the frequency of dredging. This study compares the sedimentation volume at the existing condition jetty and two alternative jetty that occur due to currents and waves, while modeling is done using Mike 21. The results of the existing jetty modeling show the sedimentation volume for 12 months was 20641.68 m3. Whereas the sedimentation volume from alternative jetty 1 and 2 produced for 12 months was 11293.56 m3 and 7426.2 m3. Modifications to the layout of the jetty provided were able to reduce the rate of sedimentation in Dock C, with the most optimal sedimentation volume for 12 months at 13215.48 m3


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Bahtiar Bahtiar ◽  
Abdul Asis ◽  
Hetty Hetty

This study aimed to describe the activities of Tuju-Tuju Port in the period of 1990 to 2015. The Tuju-Tuju Port in Bone Regency is a port that transports various commodities produced from several areas in South Sulawesi to other areas, especially to East Nusa Tenggara and its surroundings. The result study showed the activities in Tuju-Tuju Port that the ships going in and out of Tuju-Tuju Port were crowded everyday. Even though the port condition is not yet fully adequate, the loading and loading of goods still continues. The method used was the historical method with analytical descriptive consisting heuristics, source criticism, interpretation, and writing. The Tuju-Tuju Port in Bone Regency is a companion port from other ports in Bone Regency. The Tuju-Tuju Port can affect the local economy, such as increasing regional income and opening up job opportunities for the productive ages. The Tuju-Tuju Port over time has also developed the existing loading and unloading system with simple facilities and infrastructure in Tuju-Tuju Port. Daily activities continue, so the ships that are leaning on the pier and waiting for departure scheduled are crowded adorning the harbor. 


2021 ◽  
Vol 11 (24) ◽  
pp. 11837
Author(s):  
Pei Zhang ◽  
Shijia Ding ◽  
Kang Fei

In order to study the shear behavior of the interface between sand and structure, a series of shear tests were carried out using an HJ-1 ring shear apparatus (Nanjing, China). First, through the monotonic shear tests, the loose sand and dense sand were sheared at the steel interface with different roughnesses. The results showed that when the interface was relatively smooth, the shear stress–shear displacement curves of loose sand and dense sand both exhibit strain hardening characteristics. When the interface was rough, the dense sand showed strain softening. The initial shear stiffness of the sand–steel interface increased with the increase in normal stress, interface roughness, or sand relative density. Then, considering the influence of initial shear stress, through the cyclic shear test, this work analyzed the shape of the loading and unloading curves and the development law of cumulative normal deformation, and discussed the change of loading and unloading shear stiffness under different stress level amplitudes and the residual deformation generated during the cycle. The research results showed that loose sand and dense sand generally shrunk in volume during the cycle. The initial loading process was similar to the case of static loading. In the later dynamic loading process, the shear shrinkage per cycle was relatively small and continued to develop. Additionally, it was found that the unloading stiffness of the sand–steel interface is always greater than the initial loading stiffness. As the number of cycles increases, the loading stiffness increases, and it may eventually approach the unloading stiffness.


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