How the growth rate influences low-carbon sustainable production performance under different disposabilities in China’s manufacturing industries?

2020 ◽  
Vol 249 ◽  
pp. 119349 ◽  
Author(s):  
Wei zhang ◽  
Weiwen Lin ◽  
Zhenpeng Li
2021 ◽  
Vol 11 (1) ◽  
pp. 329-338 ◽  
Author(s):  
E. Surojo ◽  
J. Anindito ◽  
F. Paundra ◽  
A. R. Prabowo ◽  
E. P. Budiana ◽  
...  

Abstract Underwater wet welding (UWW) is widely used in repair of offshore constructions and underwater pipelines by the shielded metal arc welding (SMAW) method. They are subjected the dynamic load due to sea water flow. In this condition, they can experience the fatigue failure. This study was aimed to determine the effect of water flow speed (0 m/s, 1 m/s, and 2 m/s) and water depth (2.5 m and 5 m) on the crack growth rate of underwater wet welded low carbon steel SS400. Underwater wet welding processes were conducted using E6013 electrode (RB26) with a diameter of 4 mm, type of negative electrode polarity and constant electric current and welding speed of 90 A and 1.5 mm/s respectively. In air welding process was also conducted for comparison. Compared to in air welded joint, underwater wet welded joints have more weld defects including porosity, incomplete penetration and irregular surface. Fatigue crack growth rate of underwater wet welded joints will decrease as water depth increases and water flow rate decreases. It is represented by Paris's constant, where specimens in air welding, 2.5 m and 5 m water depth have average Paris's constant of 8.16, 7.54 and 5.56 respectively. The increasing water depth will cause the formation of Acicular Ferrite structure which has high fatigue crack resistance. The higher the water flow rate, the higher the welding defects, thereby reducing the fatigue crack resistance.


1990 ◽  
Vol 132 ◽  
pp. 71-91 ◽  
Author(s):  
Nicholas Oulton

What accounts for the productivity improvement experienced in manufacturing since 1979? Answers to this question are sought from a regression analysis of 93 manufacturing industries over the period 1971-86. The main findings are that when other influences, such as raw material prices and the shock of the 1980-1 recession, are eliminated, there has been an improvement in the 1980s in the growth rate of productivity whose impact effect averaged 4 per cent per annum. Between a quarter and a half of this is attributable to a decline in the disadvantages of unionisation.


2017 ◽  
Vol 8 (2) ◽  
pp. 747
Author(s):  
Fazril Saputra ◽  
Dinamella Wahjuningrum ◽  
Kustiariyah Tarman ◽  
Irzal Effendi

<em>This study aimed to determine the best dose of administration of marine fungal <span style="text-decoration: underline;">Nodulisporium</span> sp. KT29 metabolites to improve the production performance of marine culture of white shrimp. The experimental animals used were white shrimp <span style="text-decoration: underline;">Litopenaeus</span> <span style="text-decoration: underline;">vannamei</span> post larvae 12, which were reared in the sea using floating net cages with a stocking density of 700 post larvae/net. Experimental design used was a completely randomized design consisting of 3 treatments with 3 replications; control without the administration of <span style="text-decoration: underline;">Nodulisporium</span> sp. KT29 metabolites, dietary of feed containing <span style="text-decoration: underline;">Nodulisporium</span> sp. KT29 metabolites at doses of 20 mL/kg of feed and 40 mL/kg of feed. The results showed that survival rate, absolute length growth, weight gain, daily growth rate and feed conversion ratio in treatment groups were better than the control (P&lt;0.05). The administration of marine fungal <span style="text-decoration: underline;">Nodulisporium</span> sp. KT29 metabolites at a dose of 20 mL/kg of feed could improve the production performance of white shrimp cultivated in the sea with survival rate, daily growth rate and feed conversion ratio: 66.61±6.94%, 20.18±0.39 %/day and 3.20±0.22, respectively.</em>


2021 ◽  
Vol 21 (2) ◽  
pp. 89-104
Author(s):  
Riska Puluhulawa ◽  
Tatag Budiardi ◽  
Iis Diatin ◽  
Irzal Effendi

Efforts to improve the production performance of clown loach in recirculate aquaculture system can be done by increasing stocking density and water discharge. This study aimed to analyze the effect of increasing stocking density and water discharge on production performance, stress response and water quality in order to obtain the best stocking density and water discharge to obtain maximum profit in a short time. A factorial completely randomized design with two factors, i.e. the stocking density of 1, 2, and 3 fish L-1 and the water discharge of 0,05; 0,10; 0,15 L s-1 was performed. The volume of water used in each aquarium was 48 L and using a ½ inch faucet stop to regulate the water discharge from the inlet pipe. Clown fish fed Tubifex sp. with a feeding frequency of two times a day according to the treatment for 60 days. The result indicates that there was no interaction between the two factors on production performance, payback period, and R/C ratio. Stocking density has a significant effect on specific growth rate, absolute growth rate of individual weight, feeding consumption rate and R/C ratio of clown loach. Stocking density and water discharge had an interaction on the visual color of pectoral and caudal fins of clown loach. Different stocking densities with the combination of water discharge in this study resulted that the water quality were within tolerable range for clown loach so that they did not experience stress, as well as high production and business performance. It is recommended to intensify clown loach with a stocking density of 3 fish L-1 and 0,15 L s-1‑ of water discharge.


2020 ◽  
Vol 20 (2) ◽  
pp. 117
Author(s):  
Eko Harianto ◽  
Eddy Supriyono ◽  
Tatag Budiardi ◽  
Ridwan Affandi ◽  
Yani Hadiroseyani

Aquaculture is is often constrained by the availability of water, both in quality and quantity. The aim of this study was to determine the optimum maintenance system of elver (Anguilla bicolor bicolor) on a wet, moist and dry system through production performance studies and physiological responses. The research was conducted from August to September 2018 at the Production Technic and Management of Aquaculture Laboratory, Department of Aquaculture, IPB University. A completely randomized design with 5 treatments and 3 replications was used in this study, namely treatment with high water wet system 0% of body height (A), high water wet system 50% of body height (B), high water wet system 100% of body height (C), moist system (D), and dry system (E). The body weight of elver was 18.80 ± 0.62 g which derived from fish cultivator in Bogor, West Java. Fish was fed 3 times per day at satiation with commercial feed which a protein content of 50%. Results showed that treatment C was the best result with survival rate of 100%, the specific growth rate of 0.45% day -1, the absolute growth rate of 0.07 g day 1 and feed conversion ratio of 6.57. The analysis of variance showed that the treatments showed the significant effect (P <0.05). The blood glucose value closest to the eel condition before treatment was found in the treatment C.


Omni-Akuatika ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 47
Author(s):  
Titik Susilowati ◽  
Agus Nadlir ◽  
Alfabetian Harjuno Condro Haditomo ◽  
Seto Windarto ◽  
Dicky Harwanto ◽  
...  

Gracilaria verrucosa is one type of seaweed that can be developed into a high-value product. Market demand for agar reaches 21.8% per year, but only 13.1% can be met. This is due to the low level of production of G. verrucosa in Indonesia. Utilization of G. verrucosa is still relying on aquaculture from the farm, which causes low production. Cultivation of seaweed with verticulture methods can increase the production of G. verrucosa. Karimunjawa is a potential area for seaweed cultivation. The aim of this study is to determine the effect of different density areas on the growth and production of G. Verrucosa and to determine the best density area for its production in Karimunjawa. This research used G. verrucosa wrapped in a mesh size of 0.5cm with a weight of 50g per pack. Each verticulture strap contains 4 packs and each treatment consists of 9 straps. The treatment was in the form of differences in the planting area of 25x25cm2 (A), 50x50cm2 (B) and 75x75cm2 (C). The results showed significant differences (P <0.01) between each treatment. The 75x75cm2 area has the best yield on absolute growth, relative growth rate (RGR) and specific growth rate (SGR) of 83.10 ± 4.12g; 3.96 ± 0.20% / day and 2.33 ± 0.07% / day. The best results of G. verrucosa production obtained at an area of 50x50cm2 (5.32 ± 0.26 kg / m2).


Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2455 ◽  
Author(s):  
Timothy Ciarkowski ◽  
Noah Allen ◽  
Eric Carlson ◽  
Robert McCarthy ◽  
Chris Youtsey ◽  
...  

Carbon, a compensator in GaN, is an inherent part of the organometallic vapor phase epitaxy (OMVPE) environment due to the use of organometallic sources. In this study, the impact of growth conditions are explored on the incorporation of carbon in GaN prepared via OMVPE on pseudo-bulk GaN wafers (in several cases, identical growths were performed on GaN-on-Al2O3 templates for comparison purposes). Growth conditions with different growth efficiencies but identical ammonia molar flows, when normalized for growth rate, resulted in identical carbon incorporation. It is concluded that only trimethylgallium which contributes to growth of the GaN layer contributes to carbon incorporation. Carbon incorporation was found to decrease proportionally with increasing ammonia molar flow, when normalized for growth rate. Ammonia molar flow divided by growth rate is proposed as a reactor independent predictor of carbon incorporation as opposed to the often-reported input V/III ratio. A low carbon concentration of 7.3 × 1014 atoms/cm3 (prepared at a growth rate of 0.57 µm/h) was obtained by optimizing growth conditions for GaN grown on pseudo-bulk GaN substrates.


1992 ◽  
Vol 114 (3) ◽  
pp. 317-322 ◽  
Author(s):  
Y. Nagase ◽  
S. Suzuki

Fatigue behavior of plain specimens of low carbon steel subjected to small tensile prestrain is investigated through rotating bending tests and the mechanism of the decrease of fatigue limit due to the prestrain is discussed. It is found that 3 percent prestraining causes the acceleration of both slip and crack initiations, and increases the growth rate of a small surface crack of less than 0.3 mm. It also decreases the fatigue limit. If prestrained material is aged, the fatigue limit increases. These effects of the small prestrain are explained based on the unpinning of locked dislocations due to the prestrain.


Author(s):  
Dongsun Lee ◽  
Hide-aki Nishikawa ◽  
Yasuji Oda ◽  
Hiroshi Noguchi

In order to investigate the effects of hydrogen on the fatigue crack growth behavior of low carbon steel JIS S10C, bending fatigue tests were carried out using a specimen with a small blind artificial hole in a low pressure pure hydrogen gas atmosphere. The results show that the fatigue crack growth rate in hydrogen gas is higher than that in nitrogen gas, moreover, the degree of acceleration is greater in the high strain range. In fractography, intergranular facets mixed with ductile fracture and quasi-cleavage fracture with brittle striations appear in a hydrogen gas environment, while only ductile fracture mainly appears in nitrogen gas. In the low growth rate range, many intergranular facets are seen on the ductile fracture surface, and in the higher growth rate range, quasi-cleavage facets increase as the growth rate increases. The growth rate of a small crack in nitrogen gas can be expressed by dl/dN ∝ Δεpnl in the wide range of applied total strain range Δεt. The same type equation is also satisfied in hydrogen gas, but in the narrow range roughly from Δεt = 0.25% to Δεt = 0.37%. The fracture surface in this range shows only intergranular facets and a ductile morphology, but no quasi-cleavage fracture. Although the crack growth mechanism in hydrogen is different from that in nitrogen, observation of the mechanism of intergranular facet formation shows a similarity to the mechanism in nitrogen in which the slip-off mechanism of crack growth is valid. The formation of intergranular facets is also closely related to the slip behavior influenced by hydrogen. This means that there exists a high possibility for the application of the small crack growth law inhydrogen to not only S10C, but also to other carbon steels in which the intergranular facet appears.


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