6,869 research outputs found
Author\u27s Response to In My World: Designing Living & Learning Environments for the Young Creating Children’s Environments that Inspire and Instruct by Ro Logrippo
No full textAuthor\u27s Response to In My World: Designing Living & Learning Environments for the Young: Creating Children’s Environments that Inspire and Instruct by Ro Logripp
Ro-Ro verbinding Vuurland met het vasteland van Argentinië
No full textIn het vooronderzoek is voorbereidend werk gedaan voor het ontwerp van de Ro-Ro-haven. In het voor u liggende rapport staat beschreven hoe dit ontwerp verder is uitgewerkt. In het eerste hoofdstuk wordt een inventarisatie gemaakt welk type schip er voor dit specifieke Ro-Ro-vervoer ingezet moet worden. Na de te vervoeren lading in hoofdstuk 3 te hebben besproken wordt de indeling van het schip vastgesteld. Deze indeling moet zodanig zijn dat het aan te vereiste vervoerskapaciteit voldoet. In de daarop volgende hoofdstukken wordt het programma van eisen op nautisch gebied behandeld. Hier komen onderwerpen ter sprake zoals de breedte en vorm van de haventoegang. Binnen de haven zijn korrektie- en stopafstand en de afmetingen van de draaicirkel van groot belang voor de manoeuvreerbaarheid van de schepen. Het enorme getijverschil heeft grote invloed op het havenontwerp. Er is daarom in hoofdstuk 7 een mathematisch model van de getijkromme gemaakt waarmee een voorspelling van de waterstanden kan worden gedaan. Dit is o.a. van nut geweest bij de bepaling van de ligging van de brekerzone en de probabilistische benadering van de noodzakelijke geuldiepte. De golfbrekers moeten de haven bescherming bieden tegen golfaanval vanuit zee. Daarom is aan dit belangrijk element in het projekt veel aandacht besteed. Een interessant aspekt hierbij is ook de bepaling van de kruinhoogte. Het P.I.A.N.C. heeft strenge eisen gesteld aan de golfdoordringing bij Ro-Ro-havens i.v.m. de gevoeligheid van de lading voor bewegingen van het schip. Uitgaande van deze eisen is een diffraktieberekening gemaakt om te onderzoeken in hoeverre het ontwerp voldoet aan de P.I.A.N.C. eisen. Om een goede ladingafhandeling mogelijk te maken is een flexibele pontonkonstruktie ontworpen die bij elke getijwaterstand kan funktioneren. Daar de ponton geen stootbelasting kan opnemen is tussen schip en ponton een remmingwerk gesitueerd. Dit is berekend op een extreme stootbelasting van het Ro-Ro-schip. Tenslotte is een berekening gemaakt van de troskrachten die optreden bij windbelasting op het schip als het ligt afgemeerd.Hydraulic EngineeringCivil Engineering and Geoscience
Development overview of Ro-Ro ships
No full textRazvoj Ro-Ro brodova traje u kontinuitetu već više od 180 godina. Svoj povijesni razvoj započinje u Škotskoj gdje se pojavio prvi trajekt koji prevozi Ro-Ro teret, u ovom slučaju željezničke vagone. Ro-Ro brodovi razvijaju se usporedno s integralnim i multimodalnim prijevozom jer su i oni sami dio ovog tipa transporta. U 60-im godinama prošlog stoljeća dolazi do uspostavljanja velikog broja kratkih linija na području Sjevernog i Baltičkog mora, koje se danas nastoji ponovno oživjeti. Prednosti Ro-Ro brodova u početku su bile vidljive na kraćim relacijama no naknadno ih pokazuju i dugim relacijama. Najniža visina troškova po jedinici tereta u usporedbi sa drugim sustavima kao prvenstvena prednost Ro-Ro tehnologije omogućena je dobrim prekrcajnim normama te se danas uspješno kombinira sa drugim tehnologijama. Isključiva namjena Ro-Ro brodova je prijevoz tereta na kotačima. U uvodnom dijelu rada autor analizira i interpretira te opisuje razvoj Ro-Ro brodova kroz pojedina povijesna razdoblja, a zatim opisuje suvremeni Ro-Ro brod i njegove osnovne karakteristike. U drugom dijelu rada autor provodi analizu prometa Ro-Ro brodova na Jadranu u posljednjih 5 godina. Vezano uz to autor nudi pojedine zaključke i prijedloge. U posljednjem dijelu rada (Zaključak) dana su zaključna razmatranja o temi.The development of Ro-Ro ships has been going on continuously for more than 180 years. Its historical development begun in Scotland where the first ferry carrying Ro-Ro cargo is primarily applied, and in this case railway wagons. Ro-Ro ships are being developed parallel with integrated and multimodal transport because they themselves are part of this type of transportation. In the 1960s, a large number of short lines were established in the North and Baltic Seas, which are now being revived. The advantages of Ro-Ro boats were initially visible on shorter distances, but later they also showed them on long distances. The lowest cost per unit of cargo compared to other systems as a primary advantage of ro - ro technology is provided by good transhipment standards and today is successfully combined with other technologies. The exclusive purpose of Ro-Ro boats is to transport cargo on wheels. In the introductory part of the paper, the author analyzes and interprets and describes the development of Ro-Ro boats through certain historical periods, and then describes the modern Ro-Ro ship and its basic characteristics. In the second part of the paper, the author analyzes the traffic of Ro-Ro boats in the Adriatic sea in the last 5 years. In this regard, the author offers some conclusions and suggestions.
In the last part of the paper (Conclusion), concluding remarks on the topic are given
Direct numerical simulation of weakly spanwise-rotating turbulent plane Couette flow
No full textIn this report, we conduct direct numerical simulations (DNS) of weakly spanwise-rotating plane Couette flows at Reynolds number (here, is the half the wall velocity difference, and is half-channel height). A series of simulations with different rotation numbers ( is constant angular velocity component in the spanwise direction) is carried out to investigate the effect of on the flow statistics. Our results show that the flow statistics are affected by the , and a "critical" rotation number (between and ) is observed, where the kinetic energy of secondary flow contributes about a half of the turbulent kinetic energy, and the mean shear rate at the center line reaches a minimum value. We conjecture that different mechanisms should exist around , and will be investigated further
#pi#-#pi# scattering lengths at finite temperature
No full textThe s-wave #pi#-#pi# scattering lengths a"I(T) at finite temperature T and isospin I=0,2 are calculated within the SU(2) Nambu-Jona-Lasinio model. a"2(T) dislays a singularity at the Mott temperature T_M, defined as m_#pi#(T_M)=2m_q(T_M), while a"0(T) is singular in addition at the lower temperature T_d, where m_#sigma#(T_d)=2m_#pi#(T_d), m_#sigma# and m_#pi# being the masses of the #sigma# and #pi# mesons, respectively. Numerically we find T_d=198 MeV and T_M=215 MeV. We speculate on possible experimental consequences. (orig.)Available from TIB Hannover: RO 801(94-65) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Design implications of the new harmonised probabilistic damage stability regulations
No full textIn anticipation of the forthcoming new harmonised regulations for damage stability, SOLAS Chapter II-1, proposed in IMO MSC 80 and due for enforcement in 2009, a number of ship owners and consequentially yards and classification societies are venturing to exploit the new degrees of freedom afforded by the probabilistic concept of ship subdivision. In this process, designers are finding it rather difficult to move away from the prescription mindset that has been deeply ingrained in their way of conceptualising, creating and completing a ship design. Total freedom it appears is hard to cope with and a helping hand is needed to guide them in crossing the line from prescriptive to goal-setting design. This will be facilitated considerably with improved understanding of what this concept entails and of its limitations and range of applicability. This paper represents an attempt in this direction, based on the results of a research study, financed by the Maritime and Coastguard Agency in the UK, to assess the design implications of the new harmonised rules on passenger and cargo ships
L’anthroponyme mycénien wa-ra-qi-si-ro (KH X 7)
No full textInternational audienceAbstract The Mycenaean personal name wa-ra-qi-si-ro has been interpreted as the older variant of wa-ra-pi-si-ro (PY, MY), but this hypothesis comes up against several phonetic problems. This paper proposes two alternative explanations of wa-ra-qi-si-ro: either /Wrakwsilos/, a clipping of *Wrakwsi-lāhos, compound of the root *u̯ergu̯-/*u̯regu̯- “throw” and *lāho- “stone”, or /Wrankwsilos/, a nickname derived from the adjective attested in later Greek ῥαμψός “crooked”
"Infrastructure Investment for Tomorrow, A Financing Plan to Eliminate the Deferred Maintenance on the Nation's Roads"
No full textRegan presents a long-term public investment proposal to preserve and upgrade the nation's infrastructure system. He offers a unique financing plan to eliminate much of the backlog of deferred maintenance that plagues America's roads and bridges. The plan would allow states and municipalities to get out from under this burden with a one-time upgrading program and then attain a new capacity to maintain and improve their infrastructure networks. Regan concludes that the goal of long-term investing is "to make possible sustained growth, improved productivity, and a strengthened private sector" for the next generation. A program to upgrade the nation's infrastructure base could help the United States achieve this goal.
Development of an Auto-Trim Control System for Ro-Ro Ship Carrying Heavy Cargoes
No full textIn Ro-Ro ship carrying heavy cargoes, it is very important to maintain a certain level of aft draft and the proper trim through the entire loading or discharging process. Some kinds of manual ballast control system have been generally applied so far to this practice in Ro-Ro ship. However, there is need to develop a so-called Auto-Trim Control System using some computer technology to improve the operation of those existing systems.
This paper aims at developing an Auto-Trim Control System especially for Ro-Ro ship carrying such heavy cargoes including hot coils and steel plates. The author carried out some systems analysis and design for developing the system by examining and reflecting the practices of the entire loading and discharging process.
Then a user-friendly Auto-Trim Control System has been built by interfacing the Valve Remote Control system and Tank Level & Draft Measuring system with itself. The author also provides some excellent results on the performance of the system by reporting the records of installing the system on board 4 Ro-Ro ships.Abstract
제 1 장 서론 = 1
1.1 연구의 배경 = 1
1.2 연구의 목적 = 2
제 2 장 시스템의 개요 = 3
2.1 중량화물 선적 Ro-Ro 선 하역 작업의 기본개념 = 3
2.2 Auto-Trim Control System의 기본개념 = 7
2.3 시스템 구성도 = 10
제 3 장 선미흘수 및 트림 제어 알고리듬의 개발 = 11
3.1 탱크 배치도 = 11
3.2 탱크 배정 우선순위 = 11
3.3 탱크 선택 규칙 = 12
제 4 장 Auto-trim Control System 개발 = 15
4.1 시스템 소프트웨어 구성 = 15
4.2 시스템 설계 = 16
4.3 밸브 및 펌프 작동 절차 = 21
4.4 시스템 구현 = 37
제 5 장 프로그램 실행 예 = 42
5.1 통신상태 표시줄 = 42
5.2 선박상태 표시줄 = 44
5.3 프로그램 작동 = 45
제 6 장 결론 = 58
참고문헌 = 6
High silica concentration in RO concentrate
No full textSilica scaling is one of the major scaling challenges in Reverse Osmosis (RO). The safe operation practice is to keep the silica concentration below 150 mg/L in RO concentrate. This study addresses the effects of divalent cations such as calcium and magnesium on silica scaling in a seawater RO installation used as a pretreatment to Eutectic Freeze Crystallisation (EFC). Results showed that in the absence of antiscalant and divalent cations a sustained silica concentration of approximately 280 mg/L in concentrate is possible without declining membrane permeability. At a higher concentration of divalent cations, the membrane permeability decreased. Membrane autopsy and analysing destructed membrane showed a relatively low magnesium and a high calcium concentration on the membrane after adding divalent ions into the solutions. It is concluded that in absence of divalent cations and without antiscalant the limits of 150 mg/L silica can be extended to 280 mg/L for 6–8 h.Sanitary Engineerin
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