Heap Storage Research Articles

Performance Evaluation of Low-cost Storage Structures for Onions (Allium cepa L.) Storage in Bahir Dar, Amhara Region, Ethiopia

The effect of fully ventilated storage structure, netted bags, mud-coated structure (local practice in the region), and heap storage on quality and shelf-life of onion cv. Bombay red was studied at Bahir Dar Institute of Technology in Ethiopia. The experiment was conducted in a single factor with four levels (four storage structures) with three replications. Manually harvested and cured onions were stored in different storage structures and different quality and shelf-life properties were studied for 90 d. Analysis of variance (ANOVA) and correlation was conducted by SAS 9.2 version. The lowest sprouting % (1.03), rotting % (1.81), and mold incidence % (2.73) of the onions were recorded in the onions stored in fully ventilated storage structures for 90 d. The highest marketable bulb % was observed in the fully ventilated storage structure by the 90th day of storage. On the basis of this study, the fully ventilated structure was recommended to store the onions in the studied location.

Postharvest Storage Techniques for Cassava Roots in Ghana- A Review

Cassava (<i>Manihot esculenta Crantz</i>.) a staple food assumes a significant role in solving food security issues in Africa. The various uses of the root include the production of starch, cassava chips, gari, flour, and ethanol. A few days after harvest, the roots begin to decay as a result of wounds or microbial contaminations. Because of the high perishability nature of the crop, a few techniques have been employed over the ages to prolong the crop shelf life. This paper surveys the postharvest storage of fresh cassava roots by delving into techniques such as In–field storage, Heap storage, Clamp storage, and Box storage. In present-day time peeled cassava can likewise be cold stored in a deep freezer. The in-field storage technique stores the root for an extra one year yet anyway diminishes the profitability of the land as it cannot be utilized for new harvests. Heap storage under shade trees normally balances the temperature happening during the day and along these lines shielding the tubers from overheating. Notwithstanding, stacking of the produce brings about poor ventilation thereby resulting in a fast spread of decays among the roots. For effective clamp storage, thicker soil cover might be utilized to decrease the temperature in the clamp during hot - dry conditions while care ought to be taken from keeping the roots from getting wet inside the clamp during the wet seasons. For successful box storage, the packing material ought to be moist to maintain high humidity yet not wet as this could produce microbial and mold development.

English

A 2×2×3 factorial design was used to investigate the effect of two orange-fleshed sweetpotato cultivars, three curing treatments and two homestead storage methods on the general appearance, finger-feel firmness, sweetness and overall acceptability of boiled roots. The cultivars were Apomuden and Nane, and the two homestead storage methods were the sand box and the heap storage. In-ground curing (dehaulming) and field-piled curing, for seven days and then uncured treatment were the curing options investigated. A hedonic scale ranging from 1 = extremely dislike to 5 = like extremely was used. For cultivars, the sensory scores ranged from 3.20 to 3.84 (farming season I) and 3.32 to 3.93 (farming season II), indicating good consumer preference. Curing type significantly (p 0.05) in all sensory attributes in both farming seasons except for sweetness and the heap storage had significantly higher (3.84 vs. 3.47, p<0.0001; respectively) score relative to sand box in the first year. Apart from general appearance (3.64 vs. 3.32, p = 0.002) and finger-feel firmness (3.51 vs. 3.25; p = 0.006) in which females had a significantly higher score than males in the first farming season, all the other sensory attributes were similarly ranked by males and females for both years. In-ground and field-piled curing methods, there is increased consumer acceptability and it should be encouraged. Key words: Curing, Field-piled, Gender, Sensory, in-ground, orange-fleshed sweetpotato.

Shelf life extension of sweetpotato (Ipomoea batatas (L) Lam) storage roots using household-level storage methods

Three sweetpotato cultivars; OFSP-1, OFSP-2 and WFSP were investigated for storability using two storage methods (heap vs. sand box), following curing (dehaulming, field-piled or no curing). Storage roots (SRs) were subsequently stored using either heap or sand box methods. SRs were deliberately injured and wound healing assessed over a 6-day period. Over an 11 week storage period, OFSP-2 recorded the highest weight loss (9.7%; p = 0.04), weevil damage (3.7%; p = 0.49) and rot (21%; p < 0.001). Weight loss and weevil damage were respectively 1.8-times and 23-times higher in the SRs stored in heap method compared with those in the sand box method. Except for WFSP, the wound healing score increased gradually to the 3rd or 4th day for OFSP-2 and OFSP-1 respectively before levelling off. The sand box method performed better than heap storage should be encouraged for the storage of sweetpotato SRs at the household-level.

Shelf life extension of sweetpotato roots using household-level storage method

Three sweetpotato cultivars; OFSP-1, OFSP-2 and WFSP were investigated for storability using two storage methods (heap vs. sand box), following curing (dehaulming, field-piled or no curing). Storage roots (SRs) were subsequently stored using either heap or sand box methods. SRs were deliberately injured and wound healing assessed over a 6-day period. Over an 11 week storage period, OFSP-2 recorded the highest weight loss (9.7%; p = 0.04), weevil damage (3.7%; p = 0.49) and rot (21%; p < 0.001). Weight loss and weevil damage were respectively 1.8-times and 23-times higher in the SRs stored in heap method compared with those in the sand box method. Except for WFSP, the wound healing score increased gradually to the 3rd or 4th day for OFSP-2 and OFSP-1 respectively before levelling off. The sand box method performed better than heap storage should be encouraged for the storage of sweetpotato SRs at the household-level.

On-farm storage of table and processing potatoes in heaps

Heap storage of potatoes is commonly used in many states of India to avoid distress sale at harvest, but the losses in stored potatoes are generally enormous. Spray application of CIPC (isopropyl N-(3-chlorophenyl) carbamate) at the time of storage has been recommended to inhibit sprouting and reduce total losses in potatoes up to 90 days of storage in heaps. Sprouting in tubers was inhibited and total losses in potatoes were reduced (by 58.7%) up to 90 days of storage (temp. 19–31°C, 55–90% RH) during March to June. The farmers could market 6.5% more weight of CIPC treated potatoes (cv. Kufri Pukhraj) compared to the control (untreated) tubers due to reduced total losses and fetch 55.3% higher market price than the price at the time of harvest. In processing cultivar, Kufri Chipsona-1, reducing sugar concentrations decreased from 188.1 to 22.5 mg/100 g fresh weight during storage up to 90 days and chip colour improved significantly. Stored potatoes were found highly acceptable for processing by an industry collaborator (M/s Satnam Agri Products Ltd., Jalandhar) and were used in making good quality flakes and French fries. Findings established that the improved storage technology can beneficially be used to increase remunerations from potato cultivation and to preserve the quality of processing potatoes for three months at lower storage cost.

Oxidation of coal in industrial conditions. 4. Coal temperature in heap storage

The temperature variation of coal on open storage in heaps is investigated. Analysis shows that the temperature rise on storage observed for all coal in both summer and winter, regardless of its metamorphic development, may be divided into two stages: rapid increase, followed by slower increase. The higher temperature at the end of the first stage in summer (45°C) than in winter (30°C) may be explained in that the rate of peroxide formation increases with increase in the temperature, while the content of peroxides declines. A correlation is found between the duration of the first stage and the metamorphic development of the coal (its yield of volatiles Vdaf). A similar correlation is found for the rate of temperature rise in the first stage and the coal’s metamorphic development. Analysis of the results shows that, in both summer and winter, there is an extremum at moderate metamorphic development (Vdaf = 27.3–30.5%). This confirms that the oxidation mechanism is different for coal at different metamorphic stages. Since the coal does not reach the critical temperature for self-ignition (∼60°C) on storage in both summer and winter, the coal temperature in the heap is of no interest in selecting the limiting storage time.

Experimentally determined storage and handling properties of fuel pellets made from torrefied whole-tree pine chips, logging residues and beech stem wood

Torrefaction is currently of interest for the production of a new generation of fuel pellets suitable for increasing co-firing rates at pulverised-coal power plants. However, few results have been reported on properties of pellets which can currently be produced from torrefied materials. This data is required in order to evaluate the suitability of this fuel for its primary application.The objective of this study was to obtain measured results on storage and handling properties of pellets made of torrefied pine, logging residues (with and without wheat flour binder) and beech. Experimental methods, most of which adhere to standard procedures, are described. The measured properties include calorific value, bulk density, durability, hardness and equilibrium moisture content (EMC). Additionally, EMC isotherms of torrefied beech wood are presented. The results are analysed and their influence on the feasibility of large-scale pellet production is discussed. The measured and derived values presented will be of use in determining feasibility of torrefied pellet production in offsetting the use of fossil coal.From the results the following statements can be made regarding produced pellet samples:•Feedstock choice has a strongly influence on properties of torrefied pellets.•Durability of torrefied pellets is problematic compared to wood pellets.•Outdoor heap storage of torrefied pellets is not recommended.•Logging residues do not seem to be an optimal feedstock choice for torrefied pellets.•Wheat flour does not appear suitable as binder for torrefied pellets production due to water absorption.•Pelletising using high die temperature (above 170°C) should be investigated.

Syntactic control of interference for separation logic

Separation Logic has witnessed tremendous success in recent years in reasoning about programs that deal with heap storage. Its success owes to the fundamental principle that one should keep separate areas of the heap storage separate in program reasoning. However, the way Separation Logic deals with program variables continues to be based on traditional Hoare Logic without taking any benefit of the separation principle. This has led to unwieldy proof rules suffering from lack of clarity as well as questions surrounding their soundness. In this paper, we extend the separation idea to the treatment of variables in Separation Logic, especially Concurrent Separation Logic, using the system of Syntactic Control of Interference proposed by Reynolds in 1978. We extend the original system with permission algebras, making it more powerful and able to deal with the issues of concurrent programs. The result is a streamined presentation of Concurrent Separation Logic, whose rules are memorable and soundness obvious. We also include a discussion of how the new rules impact the semantics and devise static analysis techniques to infer the required permissions automatically.

Effect of CIPC on Sprout Inhibition and Processing Quality of Potatoes Stored Under Traditional Storage Systems in India

Indigenous non-refrigerated methods like heaps and pits are used in India for short-term storage of potatoes (Solanum tuberosum L.) to avoid distress sale. Storing untreated potatoes generally results in high losses from sprouting, moisture loss and rotting. To reduce storage losses by inhibition of sprouting and to determine the suitability of stored potatoes for processing into crisps, a single spray application of a commercial formulation of 3-chlorophenyl carbamate (CIPC or chlorpropham) 50% a.i., (Oorja, United Phosphorus Limited, Mumbai, India) of CIPC (or chlorpropham) was tested on potatoes during storage from March to June under two traditional storage methods [heap (17–33 °C, 58–92% relative humidity (RH)) and pit (17–27 °C, 72–95% RH)] in 2 years [2005 up to 90 days of storage (DOS) and 2006 up to 105 DOS], using four cultivars and two rates of CIPC application (20 and 30 mg a.i. kg−1 tubers). The two rates of application were comparably effective in reducing weight losses, sprouting and sprout growth in stored tubers, and the effect was more pronounced in pit storage than in heap storage. By contrast to untreated tubers, CIPC-treated potatoes remained turgid under the two storage methods and fetched market prices comparable to those for cold-stored (2–4 °C) potatoes after 105 days of storage. Reducing sugar concentrations in treated potatoes decreased during storage especially in 2006 when the initial reducing sugar concentration was higher than in 2005. Crisp colour improved only in 2005 after 90 DOS, but it deteriorated in 2006 during storage up to 105 DOS. Sucrose concentration increased tremendously during storage in 2 years. Only one cultivar (Kufri Chipsona-1) with low initial reducing sugar concentration and less sucrose accumulation during storage could produce acceptable colour crisps after storage in both years. The remaining three cultivars—with high initial reducing sugar concentration—were suitable for processing after storage in heap and pit in 2005, but not in 2006. Stored potatoes were safe for human consumption as the CIPC residue concentrations were far below the permissible level of 10 mg kg−1 as prescribed by the European Union. Single spray application of CIPC (20 mg kg−1 treatment) can effectively reduce storage losses in potatoes stored in traditional non-refrigerated methods of heap and pit and extend the storage life by 90 to 105 days.

Separation and information hiding

We investigate proof rules for information hiding, using the formalism of separation logic. In essence, we use the separating conjunction to partition the internal resources of a module from those accessed by the module's clients. The use of a logical connective gives rise to a form of dynamic partitioning, where we track the transfer of ownership of portions of heap storage between program components. It also enables us to enforce separation in the presence of mutable data structures with embedded addresses that may be aliased.

Permission accounting in separation logic

A lightweight logical approach to race-free sharing of heap storage between concurrent threads is described, based on the notion of permission to access. Transfer of permission between threads, subdivision and combination of permission is discussed. The roots of the approach are in Boyland's [3] demonstration of the utility of fractional permissions in specifying non-interference between concurrent threads. We add the notion of counting permission, which mirrors the programming technique called permission counting. Both fractional and counting permissions permit passivity, the specification that a program can be permitted to access a heap cell yet prevented from altering it. Models of both mechanisms are described. The use of two different mechanisms is defended. Some interesting problems are acknowledged and some intriguing possibilities for future development, including the notion of resourcing as a step beyond typing, are paraded.

Separation and information hiding

We investigate proof rules for information hiding, using the recent formalism of separation logic. In essence, we use the separating conjunction to partition the internal resources of a module from those accessed by the module's clients. The use of a logical connective gives rise to a form of dynamic partitioning, where we track the transfer of ownership of portions of heap storage between program components. It also enables us to enforce separation in the presence of mutable data structures with embedded addresses that may be aliased.

Task dependence and termination in Ada

This article analyzes the semantics of task dependence and termination in Ada. We use a contour model of Ada tasking in examining the implications of and possible motivation for the rules that determine when procedures and tasks terminate during execution of an Ada program. The termination rules prevent the data that belong to run-time instances of scope units from being deallocated prematurely, but they are unnecessarily conservative in this regard. For task instances that are created by invoking a storage allocator, we show that the conservative termination policy allows heap storage to be managed more efficiently than a less conservative policy. The article also examines the manner in which the termination rules affect the synchronization of concurrent tasks. Master-slave and client-server applications are considered. We show that the rules for distributed termination of concurrent tasks guarantee that a task terminates only if it can no longer affect the outcome of an execution. The article is meant to give programmers a better understanding of Ada tasking and to help language designers assess the strengths and weaknesses of the termination model.

CST

C State transformers (CST) is an expression oriented dialect of C designed to smoothly integrate functional programming into C based software. C State Transformers is an attempt to do for functional programming what C++ did for object oriented programming. It provides support for functional programming with a C like syntax. In many ways, CST programs are similar to C programs. Data definitions and function declarations have the same syntax and semantics. CST uses C’s type system. CST programs require the same run time system as C programs. A CST compiler can be implemented by the composition of a preprocessor and a C compiler. In contrast with C, the body of a CST function definition is an expression. CST has no statements and its iteration construct produces a value upon termination. CST allows purely functional computations to be specified in a natural, expression oriented manner. CST’s support for functional programming is limited due to the requirement that there be a simple translation of the language into C. As a result, CST programs must explicitly manage heap storage and a function cannot be the result of another function if its body references a local variable in the producing function. The limitations on functional programming allow the seamless integration of CST modules into C programs. As an added bonus, the language is simpler than C.

Atomic garbage collection: managing a stable heap

Modern database systems use transactions to achieve a high degree of fault-tolerance. Many modern programming languages and systems provide garbage collected heap storage, which frees the programmer from the job of explicitly deallocating storage. In this paper we describe integrated garbage collection and recovery algorithms for managing a stable heap in which accessible objects survive both system crashes and media failures. A garbage collector typically both moves and modifies objects which can lead to problems when the heap is stable because a system crash after the start of collection but before enough of the reorganized heap reaches the disk can leave the disk in an inconsistent state. Furthermore, collection has to be coordinated with the recovery system. We present a collection algorithm and recovery system that solves these problems.

An efficient algorithm for heap storage allocation

An efficient algorithm for heap storage allocation

Global garbage collection for distributed heap storage systems

We present a garbage-collection algorithm, suitable for loosely-coupled multiprocessor systems, in which the processing elements (PEs) share only the communication medium. The algorithm is global, i.e., it involves all the PEs in the system. It allows space compaction, and it uses a system-wide marking phase to mark all accessible objects where a combination of parallel breadth-first/depth-first strategies is used for tracing the object-graphs according to a decentralized credit mechanism that regulates the number of garbage collection messages in the system. The credit mechanism is crucial for determining the space requirement of the garbage-collection messages. Also a variation of this algorithm is presented for systems with high locality of reference. It allows each PE to perform first its local garbage collection and only invokes the global garbage collection when the freed space by the local collector is insufficient.

A real-time garbage collector based on the lifetimes of objects

In previous heap storage systems, the cost of creating objects and garbage collection is independent of the lifetime of the object. Since objects with short lifetimes account for a large portion of storage use, it is worth optimizing a garbage collector to reclaim storage for these objects more quickly. The garbage collector should spend proportionately less effort reclaiming objects with longer lifetimes. We present a garbage collection algorithm that (1) makes storage for short-lived objects cheaper than storage for long-lived objects, (2) that operates in real time—object creation and access times are bounded, (3) increases locality of reference, for better virtual memory performance, (4) works well with multiple processors and a large address space.

Hardware/software cooperation in the iAPX-432

The Intel iAPX-432 is an object-based microcomputer system with a unified approach to the design and use of its architecture, operating system, and primary programming language. The concrete architecture of the 432 incorporates hardware support for data abstraction, small protection domains, and language-oriented run-time environments. It also uses its object-orientation to provide hardware support for dynamic heap storage management, interprocess communication, and processor dispatching. We begin with an overview of the 432 architecture so readers unfamiliar with its basic concepts will be able to follow the succeeding discussion without the need to consult the references. Following that, we introduce the various forms of hardware/software cooperation and the criteria by which a function or service is selected for migration. This is followed by several of the more interesting examples of hardware/software cooperation in the 432. A comparison of cooperation in the 432 with several contemporary machines and discussions of development issues, past and future, complete the paper.