Invisible Losses Research Articles

Total Productive Maintenance - Accelerating OEE in a Manufacturing Industry Leveraging Pervasive Technologies

Total productive maintenance (TPM) is a people-intensive, preventive maintenance system for maximizing equipment effectiveness in the enterprise. The concept of TPM was originally suggested by Nakajima (1988) who proposed overall equipment effectiveness (OEE) as a metric for evaluating the progress of TPM, which is interpreted as the multiplication of availability, performance and quality. This paper aims to study and investigate the implementation of a TPM to improve the OEE in manufacturing enterprises. In today’s industrial scenario huge losses occur in the manufacturing shop floor. These losses are due to operators, maintenance personal, process, tooling problems and non-availability of components in time etc. The quality related waste are of significant importance as they matter the company in terms of time, material and the hard earned reputation of the company. There are also other invisible losses like operating the machines below the rated speed, start up loss, break down of the machines and bottle necks in process. Zero oriented concepts such as zero tolerance for losses, defects, break down and zero accidents are becoming a pre-requisite in the manufacturing and assembly industry. In this situation, a TPM is the answer to resolve the above said problems which helps in benefitting the growth prospects of any organization.

Capacity of the mechanical harvesting process of sugar cane billets

The mechanized harvest of sugar cane (Saccharum officinarum L.) in Brazil is an irreversible trend and it comes with a great concern about the quality of the cane delivered to the industry. A key component to quality is the billet length which affects the processing of raw material, cane deterioration, invisible losses and load density of transport vehicles. Thus, due to the importance of the billet standard in quality and cost of raw material, this study aimed to evaluate if the mechanized harvesting of sugar cane can supply the quality requirements for the crushing process, regarding the billet length. A plot with burnt sugar cane (3.2 ha) and another one with green sugar cane (8.0 ha) were selected to be harvested by two (2) self-propelled sugar cane harvesters. For each harvested 0.4 ha a sample from each infield wagon was collected. The sample was composed by ten billets. The variability in burnt sugar cane was higher than in green sugar cane, and both harvesters did not present the capacity of keeping the billets with similar lengths when operating either in burnt or green conditions.

From Invisibility to Transparency: Identifying the Implications

Turner, N. J., R. Gregory, C. Brooks, L. Failing, and T. Satterfield. 2008. From invisibility to transparency: identifying the implications. Ecology and Society 13(2): 7. https://doi.org/10.5751/ES-02405-130207

Revisiting the Dartmouth Court Decision: Why the US has Private Nonprofit Agencies Instead of Public Non-Governmental Organizations (NGOs)

In 1819, the US Supreme Court ruled in Dartmouth v. Woodward that Dartmouth College, even though originally chartered by government, was legally akin to a private corporation. This landmark decision was the founding legal document of what has become the American private nonprofit sector. While the decision has attained hagiographic status, this paper explores what the US nonprofit sector would look like if the Supreme Court had ruled the other way. Using alternate history and scenario writing as research methodologies, it highlights the invisible losses due to the decision and depicts what a public nonprofit sector would have looked like.

Avaliação de perdas invisíveis na colheita mecanizada em dois fluxos de massa de cana-de-açúcar

Neste trabalho, analisou-se o comportamento da colhedora de cana-de-açúcar picada frente a dois fluxos de alimentação de matéria-prima, mensurando-se as perdas invisíveis, impossíveis de serem quantificadas diretamente no campo, a eficiência de limpeza da colhedora e a velocidade do ar na saída dos extratores. Os ensaios foram realizados sob condições controladas no Centro de Tecnologia Copersucar, em janeiro de 2000. Os resultados apontaram que o fluxo de massa de cana que alimenta a colhedora, na faixa avaliada, não tem influência nas magnitudes das perdas invisíveis totais de cana e na eficiência de limpeza da matéria-prima. A velocidade média do ar na saída do extrator primário foi de 12,0 m s-1, e no extrator secundário, de 9,2 m s-1, com coeficiente de variação médio de 21%, indicando que o baixo desempenho de limpeza da colhedora pode estar associado às diferenças de velocidade do ar nos extratores. Por meio da análise dos dados quantificados nos ensaios, concluiu-se que as perdas invisíveis no processamento da cana na colhedora foram de 10%, e a eficiência de limpeza, de 87%.

Bag Silo Densities and Losses

Bag silos made at three research farms in 2000 and 2001 were monitored at filling and emptying to determine densities and losses. A total of 47 bags (23 alfalfa, 1 red clover, 23 whole-plant corn) were made, and losses were calculated on 39 of the silos. Dry matter (DM) density ranged from 160 to 270 kg/m3. Dry matter density increased with DM content in hay crop silages on average 2.9 kg/m3-% DM, whereas the effect in corn silage varied by bagging machine. Density decreased with increasing particle size at 4.1 kg DM/m3 per mm. The operator and the bagging machine setup both affected density. A wide range (0% to 40%) of DM losses was observed. Average DM losses were 9.2% invisible plus uncollected losses and 5.4% spoilage losses, for a total loss of 14.6%. Six silos had excessive spoilage losses of more than 15% and total losses above 25% due to plastic integrity issues or overly dry silage (>40% DM) being fed out in warm weather. Invisible losses were reduced in high-porosity silages (where spoilage losses were exacerbated), greater in warm weather, and affected by emptying procedures. Spoilage losses in bags without plastic integrity issues were greater in dry silages, from emptying silos in warm weather, at lower feed-out rates, in bags stored for a long time, and if bags were emptied periodically rather than daily.

Dancing in Limbo: Making Sense of Life after Cancer

Halvorson-Boyd, Glenna and Hunter, Lisa K. (1995). Dancing Limbo: Making Sense of Life After Cancer. San Francisco, CA: Jossey-Bass. 177 pages. Hardcover ISBN 0-7879-0103-2, price $28.50 Canada, $21.00 U.S. Much has been written about the technical and medical aspects of cancer its various forms, as well as the broad range of traditional and alternative therapies used treating the disease. In contrast to the myriad existing publications about cancer, Dancing Limbo is one of the first books to address the experience of diagnosis and living with the disease from the cancer survivor's perspective. The overall purpose of the book is to dismantle an inaccurate myth that surrounds the cancer experience: surviving the disease ends happily ever after. In contrast to this common perception, the reality that the authors portray is that having cancer is a profoundly life altering experience. Facing the everlasting threat of death that comes with the disease means that life will never return to normal as it was once known-even if one is cured. The uncertainty of cancer means that, for those fortunate to survive, life will always be in because one never knows if they are death row. This uncertainty requires that cancer survivors redefine their existence and relearn the dance of life. This awareness is critical to the effective care of cancer survivors, yet it is often unknown to or misunderstood by the family, friends, colleagues, health practitioners, and other professionals involved their lives. Dancing Limbo is based on a phenomenological approach aimed at capturing the `lived experience' of surviving cancer. In each of eight chapters, selections from the authors' own journal entries, as well as quotations from interviews with five men and twelve women who are at various stages of recovery, illustrate the key themes being diagnosed and learning to live with the disease. Halvorson-Boyd and Hunter begin by defining the concept of by telling the history of their own experiences as cancer survivors. Throughout each chapter that follows, the full meaning of limbo emerges as they continue to weave their stories together with those of their research participants. In the first half of the book, the authors provide a candid look into the fears and questions that often torment those diagnosed with cancer. Chapter two explores the confusion and disorientation that survivors encounter as they attempt to resume their daily lives. This chapter also describes the role of psychological defenses helping survivors deal with their feelings of fear and helplessness. The third chapter addresses the primary question that haunts most cancer patients: Why me? The chapter examines the ways that survivors seek to answer this insoluble question an attempt to understand and accept the meaning of their illness and their lives. Chapters four and five describe the specific struggles that survivors confront with fears of recurrence, death anxiety, and the process of grieving both the visible and invisible losses their lives. …

The effects of incorporating sugar‐beet pulp with herbage at ensiling on silage fermentation, effluent output and in‐silo losses

AbstractThree studies were undertaken with the aim of examining in‐silo losses associated with ensiling mixtures of beet pulp and herbage. In Experiment 1, first‐regrowth perennial ryegrass was ensiled untreated or mixed with either 40 or 120 kg unmolassed beet pulp t−1 fresh grass prior to ensiling. In each of Experiments 2 and 3, second‐regrowth ryegrass was ensiled untreated or mixed with either 40, 80 or 120 kg unmolassed beet pulp t−1 fresh grass prior to ensiling. Dry‐matter concentrations of herbage ensiled in Experiments 1, 2 and 3 were 141, 157 and 139 g kg−1 respectively.Time‐course studies indicated a more rapid fermentation with the untreated silages. Ensiling beet pulp with herbage resulted in significant improvements in silage fermentation, reflected in reductions in silage pH and ammonia nitrogen concentrations, with these effects being pronounced at beet pulp inclusion in excess of 80kg t−1. Beet pulp inclusion increased the dry‐matter concentrations of the resulting silages while reducing crude protein, modified acid detergent fibre and gross energy concentrations. In Experiment 1 beet pulp retained 1·62 and 1·641 effluent kg−1 at the 40 and 120kg t−1 application rates respectively. In Experiments 2 and 3, effluent retentions were 1·40, 1·29 and 0·93 1 kg−1 and 2·87, 2·19 and 1·781 kg−1 at the 40, 80 and 120kg t−1 beet pulp inclusion rates respectively. In each of Experiments 1 and 3, in‐silo losses were reduced with increasing level of beet pulp inclusion, while in Experiment 2 in‐silo losses were relatively unaffected by treatment. Nutrient losses in effluent were reduced by the inclusion of beet pulp in all three experiments, while nutrient losses in surface waste and invisible nutrient losses tended to increase with higher levels of beet pulp inclusion.It is concluded that the inclusion of beet pulp with herbage at ensiling can result in an improved silage fermentation and a reduction in in‐silo losses, while at the same time retaining considerable quantities of effluent within the silo. However, with herbage dry‐matter concentrations below 160gkg−1, beet pulp inclusion in excess of 120 kg t−1 herbage would be required to eliminate effluent production totally.

A review of losses arising during conservation of grass forage: Part 2, storage losses

Information from the literature about hay and silage storage losses has been reviewed, compared and analysed. An attempt has been made to summarize the information in terms of relationships, suitable for incorporation in an operational research model of forage conservation. Hay storage losses are low and can be related solely to moisture content. In contrast, silage storage losses are much larger, often 20% or more, and the subject is complex. Silage storage losses have been subdivided according to the mechanism by which they arise into fermentation loss, air infiltration losses and effluent loss. Air infiltration losses arise when silos are filled, during the storage period, and while feeding out, and consist of both invisible losses through oxidation of nutrients, and silage which is visibly spoilt due to serious oxidation or overheating so it is unusable. Experimental and modelling studies on the processes of fermentation of silage, air infiltration to silage, and the resulting losses, are discussed. Air infiltration losses are related to density and chop length, and information about values of these factors is also reviewed. From this information, a table of typical loss values has been assembled in relation to dry matter content, chop length, grass maturity, and the use of additives. These represent the best currently available average figures, bearing in mind some uncertainties and inconsistencies in the source material. However, for the forage conservation model, a long-term aim has been identified, namely, to express losses by values estimated from models of the physical processes, which are just now being developed. Information about effluent loss was consistent across a number of sources; it could be summarized as a simple relationship between percentage loss and dry matter content.

An Alternative Method for Determining Lint Cleaner Efficiency

ABSTRACT Astudy was conducted to improve the accuracy in determining the foreign matter content in lint cotton and the cleaning efficiency of saw-cylinder lint cleaners. Foreign matter content and cleaning efficiency are presently calculated from total waste figures as measured by the Shirley Analyser procedure. This tends to give lower than actual efficiency when processing cottons because of high invisible waste losses. In the experiments about 75% of the foreign matter in the lint was Shirley Analyser visible waste before lint cleaning and, after extensive lint cleaning, 75% of the foreign matter remaining in the lint was Shirley Analyser invisible waste. Thus, the standard procedure does not adequately describe the degree of cleaning obtained. Relationships were studied and an alternative method developed to ascertain an efficiency more nearly based on the actual foreign matter content instead of the total waste figure now used. This work should contribute to establishing a new standard, which is less affected by invisible losses than the present procedure.

Nutrient Losses and Silage Quality as Affected by Rate of Filling and Soybran Flakes

Summary Two silos were filled rapidly and two slowly with high-moisture forage. Soybran flakes were added to one silo of each of the filling rates. Total losses of dry matter, protein, nitrogen-free-extract, and ash were lower in the rapidly filled silos. Most of these differences were accounted for by changes in invisible losses, as the seepage portion was not greatly affected. The rate of filling had little effect on crude fiber losses. Silage from the rapidly filled silos contained more lactic acid, but less acetic, propionic, and butyric scids. When soybran flakes were added, the rate of filling had little effect on pH, but without additive slow-filling increased this value. The slow rate of filling resulted in higher peak temperatures which persisted longer. Addition of the soybran flakes reduced the amounts of dry matter and protein lost by seepage but increased invisible losses. Total dry matter and nitrogen-free-extract losses were increased with the additive; whereas, the relative losses of ash and ether extract were reduced. Persistency of milk production and weight gains were excellent for all groups and no significant differences were associated with rate of filling or addition of soybran flakes. The high rate of concentrates fed, apparently, was effective in overcoming most of the detrimental effects of feeding silage from the slowly filled silos on these measures. Cows fed from the slowly filled silo without additive consumed somewhat less silage dry matter than any other group.

Measurement of Fish for Liberation by Weighing

Abstract Accurate measurement of fish produced is essential before the production or efficiency of hatcheries can be compared or evaluated correctly. Where large numbers of fish are liberated, a system of weighing offers an easy and accurate method. Precautions are necessary to assure accurate representative samples of the fish being counted. Large errors occur if seine samples from ponds are depended upon as average samples. Most accurate results are obtained when fish are seined into holding pens and 5- to 10-pound samples of each 100-pound load of fish are counted. Invisible losses occasioned by cannibalism, predators and unseen escapement often are unexpectedly high. Even when a very accurate record is maintained of all observed losses, the number of fish weighed out of the ponds is much less than hatchery records indicate. Conditioning of the fish before hauling is desirable when long truck hauls are necessary. This may be done by not feeding them for 24 to 36 hours. Losses occasioned by overloading ...

An investigation of invisible losses in expeller operation

Description and results of a test run on a single Expeller mill set up for cotton seed crushing to determine losses. A material balance is included showing that the unaccounted for loss in the process was very small.