Sugar Factory Research Articles

E-SOURCING STRATEGIES ON EFFICIENCY OF PROCUREMENT PROCESSES OF SUGAR FACTORIES IN KENYA

Sugar factories are increasingly confronted with greater global competition and changing markets environment despite their effort to use e-sourcing strategies as a key pillar to improve procurement performance. This has resulted in unnecessarily high operation costs, poor inventory control, unacceptable supplier appraisal standards and uncoordinated business activities in the procurement positions, thus affecting general performance. E-sourcing has become a powerful tool which facilitates accountability and audit-ability. This study sought to determine the effect of e- sourcing strategies on efficiency of procurement process of Sugar factories in Kenya. The study adopted a correlational research design where the target population was 165 who were the Head of Agriculture, Head of Finance, Head of Manufacturing, Head of ICT, Head of Marketing, Head of Purchasing and Procurement staff working in sugar factories in Kenya. The study findings are presented in form of tables, figures and graphs. The e-sourcing strategies; e-tendering strategy, e-prequalification strategy and e-evaluation strategy could only explain 59.8% of efficient procurement performance as shown by R2 of 0.598. The study recommends that sugar factories suppliers should procure document management software which will enables them to register their suppliers online and submitted their mandatory requirements online. The results of this research may guide in policy formulation for the sugar sub sector. KEY WORDS: E-Evaluation, E-Prequalification, E- Sourcing, E-Tendering, Efficiency of procurement process

Scrupulous analysis of the carbon footprint of sustainable electricity produced from raw bagasse, torrefied bagasse, and filter cake pellets in Thailand

This study evaluates the carbon footprint of a 25 MW biomass power plant in a sugar factory, focusing on its 8 MW grid supply. Six key activities were assessed: fuel preparation, combustion, power generation, particulate removal, and water production (soft and cooling). The research compares greenhouse gas (GHG) emission from three scenarios: 100 % raw bagasse (RB), RB mixed with torrefied bagasse (TB), and RB with filter cake pellets (FP) at ratios of 95:5, 97:3, and 99:1. Data collected throughout 2023 revealed that the plant consumed 119,769.89 tons of RB (51 % moisture, 7740.40 kJ/kg heating value), generating 31,552,711.00 kWh annually. Emissions were calculated in kg CO2eq/kWh using the 2006 IPCC Guideline (The Intergovernmental Panel on Climate Change). Results showed that 100 % RB emitted (0.184+0.006, −0.005) kg CO2eq/kWh. Incorporating TB reduced emissions to 5 % = (0.178±0.005), 3 % = (0.178+0.006, −0.005) and 1 % = (0.178+0.006, −0.005) kg CO2eq/kWh due to decreased diesel oil, electricity, and steam usage in fuel preparation. Remarkably, using FP further decreased emissions, with 5 % FP resulting in negative total GHG emissions of (-0.225+0.015, −0.017) kg CO2eq/kWh, primarily due to the FP preparation process (-15,096,234.40±56,716.07 kg CO2eq/year). The study concludes that combining RB with TB or FP significantly reduces emissions and increases electricity production 5 % torrefied bagasse decreased 0.30 %, 3 % torrefied bagasse decreased 1.34 % and 1 % torrefied bagasse decreased 2.41 %, 5 % pelletized filter cake decreased 229.95 %, 3 % pelletized filter cake decreased 139.77 % and 1 % pelletized filter cake decreased 48.77 % by compare raw bagasse 100 %, promoting sustainable energy generation. These findings encourage the use of biomass for sustainable and environmentally advantageous power production.

Barriers influencing the sustainable development of community-based tourism (CBT): evidence from Ciaotou heritage village in Taiwan

PurposeIn recent years, community-based tourism (CBT) in the global market has been combined with specific themes in order to establish various tourism activities. Relatively few studies have comprehensively investigated how this type of CBT should be developed. Therefore, this study takes CBT with festival themes combined with community characteristics as a case study, which explores what obstacles exist in CBT with a combination of community characteristics – the industrial history of sugar factories and external themes, such as, formal flower displays.Design/methodology/approachThe thematic analysis is employed for data analysis of interviews. All interview participants were stakeholders.FindingsThis study identifies five types of obstacles: policy-related, environmental-related, innovation-related, industry-related and communication-related. Based on these findings, it is vital to consider both community and other characteristics of CBT. At the same time, after evaluating the rational perceptions of different stakeholders within the same type of obstacle, this study proposes a more specific and comprehensive development strategies for CBT.Originality/valueTo the best of the authors' knowledge, this is the first study of community agricultural tourism which collected the viewpoints of different stakeholders – tourists, residents, community associations, local businesses and the government. This study employs in-depth analysis of external policies and environmental and agricultural factors to discover and develop relevant coping strategies and implications.

A meta-analysis of the impact of water-solved pollutants on the protein content of Pistia stratiotes L.

Due to the high cost of conventional water cleaning procedures, an affordable alternative for developing countries is the use of Pistia stratiotes L. Although these plants adsorb toxic chemicals in their tissues, other studies report a high protein content in its biomass and propose to use it as a fodder or even for human consumption. Therefore, this study aimed to identify the impact of water-solved pollutants on the content of protein in the tissues of P. stratiotes through a meta-analysis of currently available literature. Scientific reports, which included the biochemical analysis of the species when exposed to pollutants in the growing media were retrieved. The statistical analysis identified that chromium, wastewater sludge from a sugar factory, fluoride and linear alkyl benzene sulphonate reduce the content of protein. On the contrary, metals such as copper and zinc showed a slight tendency to promote the accumulation of protein in the biomass. Only the use of municipal wastewater sludge consistently promoted the increase of protein. Since most pollutants reduced the protein content and others also pose a bioaccumulation risk, P. stratiotes is not recommended to be considered as a fodder or to be included in human diet without previously ensuring its chemical innocuity.

Sulfur dioxide in white sugar: Source of income, reference values

Sulfur dioxide is one of the classic essential technological processing aids used in modern technology for the production of white beet sugar. The technological and safe use of sulfites (sulfur dioxide, sodium sulfite and sodium hydrosulfite) in the formation of the food system of the sugar production process flow has been substantiated, and their functional effect is shown. It has been established that the change in the content of sulfur dioxide in white sugar under the influence of an antifoam, antiscale agent and decolorant in the doses used in massecuite occurred in accordance with the principle of additivity. The presence of the additive property was confirmed by the maximum approximation of the algebraic sum of the effects of each agent, amounting to 5.6%, to the range of variation in the values of the sulfur dioxide content (5.9) at a significance level of p=0.05. The dependence of the sulfur dioxide content in white sugar in a range of 0 to 6.5 mg/kg on the influence of the decolorant and defoamer in a dose range of 100 to 200 and of 4 to 6 g/t of massecuite was established. It has been revealed that increasing the minimum optimal dose of the decolorant to the maximum leads to an increase in the content of sulfur dioxide in white sugar by 1.7 times. Confidence intervals for the general mean were calculated based on the assumption of normal data distribution and a significance level of p=0.05. The reference values for the sulfur dioxide content in white sugar of the four categories were 1.28–2.69 mg/kg, and the upper limit level with consideration for the confidence interval was 1.39–3.01 mg/kg. The established reference values can be used at sugar factories in the production control system, and also provide an evidence base for comparison and assessment of this indicator of the white sugar safety for industrial consumers.

FEATURES AND EXPERIENCE OF CONVERTING GAS-OIL BOILERS OF INDUSTRIAL CHP PLANTS TO BURNING BIOMASS AND SUB-BITUMINOUS COAL

The paper examines the features of biomass as a fuel and substantiates that for agrobiomass waste with a high content of alkali metal oxides and slag properties of ash, it is more appropriate to burn it in a dense bed in the form of pellets, which ensures a temperature at the exit from the furnace of no more than 900 °C, a low part of fly ash and low content of unburned carbon in it, and so eliminates the risk of smoldering deposits with their melting and slagging. Technical solutions are given and the experience is presented of gas and oil boilers of CHP plants of sugar factories reconstruction with their transfer to the burning of biomass and/or coal in a dense bed on a direct-flow grate with the replacement of the air heater with air-water heater, with the addition of stages of the boiling economizer to compensate for the decrease in the heat perception of the furnace screens, maintaining the overall height of the boiler and the plane of the boiler cell. The reconstruction of boilers according to the developed technical solutions is possible to perform in the interval between production seasons, its implementation on boilers BKZ-75 GMA of Radekhiv and Chortkiv sugar factories allowed to achieve acceptable technical, economic and environmental indicators and ensured payback due to the difference in commercial prices of gas and of agrobiomass pellets. It is proposed to replicate the positive experience in the creation of decentralized regulating thermal generation capacities of the country. Bibl. 30, Fig. 3, Tab. 4.

Influence of dispersion of a new type whole crystals seed on crystallization process and sugar quality

The aim of the work was to study effectiveness of the influence of a new type crystal seed with different microcrystals dispersion on the process of sucrose crystallization and sugar quality. The dispersion of microcrystals of the crystal-forming agent with whole crystals was determined and curves of their differential distribution were presented, which showed the average particle sizes of the “Ester K 01” are 18.2 μm and 46.4 μm. The morphological characteristics were determined of particles of the whole crystals seed and the seed slurry produced at a sugar factory. The duration of massecuite boiling was investigated and a comparative characterization of the quality indicators of the resulting massecuite, mother liquor, and sugar was given depending on the use of the whole crystals seed with different dispersion of microcrystals in comparison with the factory slurry. Microphotographs of sugar crystals in the massecuite were obtained with their size recorded 5, 10 and 20 min after the input of various seeds. The morphology of sugar crystals was studied in the finished massecuite. A comparison is given of the granulometric composition of sugar crystals obtained with crystal-forming agents with different dispersion. It was found based on the results of the study that when using the “Ester K 01” (46.4 μm) in thick juice with high turbidity the corresponding crystals are formed faster in the total amount of the massecuite. It was also found that there is a kind of blocking of the process of adjacent growth of crystals from the particles of impurities of thick juice with high turbidity. This contributes to the formation of more uniform, homogeneous crystals of the correct shape. The results are presented in the article of tests of the whole crystal seed “Ester K 01” (18.2 μm) and “Ester K 01” (46.4 μm) at sugar factories using the method of working on the seed magma and the method of shock crystallization respectively. The dependences were obtained of the average linear size, the amount of sugar of the 0.65 mm fraction, the coefficient of variation and the coefficient of uniformity of sugar crystals on the consumption of the whole crystals seed “Ester K 01” (crystal size 46.4 μm). The regression equation was developed in natural form for the process of sucrose shock crystallization. It was established the rational consumption of the crystal-forming agent “Ester K 01” (crystal size 46.4 μm), which ensures the effective crystallization of sucrose for the process of crystallization by the shock induced method.

Improving sugarcane productivity on marginal soil in Takalar, Indonesia, through the application of sugarcane factory waste

Marginal soil with low nutrient content is a crucial problem in reducing crop productivity, including sugarcane. This study aimed to elucidate the possible improvement of the physical and chemical properties of marginal soil through the application of organic waste from sugar factories, namely kettle ash and press mud. Nine treatment combinations of 0, 10, and 20 t ha-1 of each kettle ash and press mud were arranged in a two-factor randomized factorial design with three replications. Soil organic matter, N, P, and K, soil aggregate stability, and sugarcane productivity were measured after planting sugarcane for five months. The results showed that the application of kettle ash and press mud, especially with a ratio of 20 t ha-1 kettle ash and 10 t ha-1 press mud, was able to reduce the leaching of organic matter and improve sugarcane growth, particularly increasing the number of tillers by 16%, stem height by 14%, and diameter by 16%. The sugarcane productivity obtained was 58.02 t ha-1. Other portions of kettle ash and press mud did not have a favorable effect on sugarcane productivity. This study provided practical insights for increasing agricultural productivity, especially in sugarcane plantations.

Life cycle assessment of biochar and cattle manure application in sugar beet cultivation – Insights into root yields, white sugar quality, environmental aspects in field and factory phases

Sugar beet (Beta vulgaris L.) is a well-known sugar crop essential for supplying the global demand for sugar. Examining how different farming techniques affect the environment may help produce a high-quality crop with the least negative environmental effects. To this, the life cycle assessment (LCA) of biochar (B) and cattle manure (CM) applications at three different rates (5, 10, and 15 tons ha−1) compared with conventional chemical fertilization (CH) in the autumn and spring sugar beet crops has been studied. The system boundaries for LCA analysis were set from the cradle to the sugar factory gate. Based on the results, the highest amounts of root yield were obtained under CM10 and CM15 treatments with 24.5% and 23.2% increase in autumn cultivation and 34.8%, and 33.9% increase in spring cultivation, compared to CH. However, CM15 resulted in significantly lower sugar content (10.9%) than B5 (17%). Also, B utilization significantly reduced molasses content in sugar beet rather than CM in both cultivation periods. Further, biochar treatments (B5, B10, B15) significantly increased the white sugar yield in both cultivation times by 43.7%, 39.2%, and 36.1%, on average. Generally, the highest and the lowest global warming potential (GWP) were obtained from CM15 and B15 with 638.5 and 437.2 CO2-eq ton−1 root/sugar yields, respectively. These findings validate the hypothesis that using biochar in sugar beet production could reduce greenhouse gas emissions while increasing the amount of white sugar produced.

Continental-scale insights into the sugarbeet diffusion juice microbiomes.

Bacterial contamination of raw diffusion juice poses unique challenges during the sugar extraction process. This study profiled bacterial communities by using full-length 16S rRNA amplicon sequencing and quantified the carbohydrate concentrations in raw diffusion juice samples received from sugar factory regions across the USA and Canada. Juice samples were collected at four time points during the 2021 and 2022 processing campaigns. Firmicutes was the dominant phylum from the raw diffusion juice samples collected during both campaigns and comprised 85.5% of total bacterial abundance. Lactic acid bacteria such as Leuconostoc and Lactobacillus were among the core genera which also dominated the bacterial community in raw diffusion juice. Positive correlations in the abundance of functionally and taxonomically related bacterial communities were identified. During the 2021 campaign, 44 bacterial genera were differentially abundant in raw diffusion juice extracted from sugarbeet roots in Periods 1 to 4. This number declined sixfold during the 2022 campaign to three genera. The concentration of raffinose in raw diffusion juice positively correlated to the relative abundance of Leuconostoc. Furthermore, an in vitro assay was performed to assess the growth dynamics of Leuconostoc mesenteroides in sucrose or raffinose-rich medium and observed the rapid consumption of both carbohydrates by this bacterium. This finding is important for deciphering microbial growth dynamics in raw diffusion juice that can be useful in minimizing sugar loss during the factory processing.IMPORTANCEFindings additionally provide baseline information that can be used to develop mitigation strategies that reduce losses due to microbial contamination of sucrose processing streams.

The Influence of Safety Leadership and Safety Climate on Safety Behavior is Mediated by Safety Motivation in Sugar Factory Employees

The sugar industry has complex production processes and involves various risks, including the high potential for employee accidents. To reduce this risk, the implementation of an effective work safety programme is required. This reserach aims to analyse the effect of safety leadership and safety climate on safety behaviour mediated by safety motivation in sugar factory employees. The method used is quantitative with data collection through questionnaires. The population of this study were all sugar factory employees in Indonesia, with a sample of 100 respondents selected using random sampling technique. Data analysis was carried out using Path Analysis in the SEM-PLS programme. The results showed that Safety Leadership and Safety Climate positively influence the Safety Behaviour of sugar factory employees. In addition, Safety Motivation mediates the influence of Safety Leadership and Safety Climate on Safety Behaviour, which indicates that Safety Motivation can strengthen the influence of these two factors on the safety behaviour of sugar factory employees. This reserach provides important implications for sugar factory management to pay more attention to aspects of motivation and safety climate to improve safety behaviour in the workplace.

Evaluation of Sugar Factory Privatization Practices in Turkey: The Case of Kayseri Sugar Factory- Turhal

Evaluation of Sugar Factory Privatization Practices in Turkey: The Case of Kayseri Sugar Factory- Turhal

Microorganisms in beet sugar production – perspective on technological opportunities and risks

The sugar industry has long faced challenges from microorganisms during production. Preventing sugar losses and microbial-related issues such as the formation of organic acids, gases like CO2 or H2, or slimy substances continues to be key concerns. Fortunately, process parameters such as high temperatures, low pH values and limited oxygen availability create unfriendly conditions for microorganisms, and antimicrobial agents have been developed to control microbial growth. However, a proactive approach would utilize the advantageous properties of microorganisms to break down undesirable substances and promote desirable ones. For example, acidic by-products from bacterial metabolism lower the pH and thus stabilize sugar beet cossettes during pressing. Additionally, beneficial metabolic processes have been recognized, such as preferentially utilizing monosaccharides instead of sucrose or selectively degrading undesired substances (e.g., converting nitrite into elemental nitrogen). Modern sequencing techniques continue to identify unknown bacteria with the potential to improve the process. Exploring these bacteria could offer valuable insights for a better microorganism management in beet sugar production. This perspective article discusses the microbial diversity in beet sugar factories and strategies for better utilization of microbial benefits, aiming for sustainable improvements in sucrose extraction. However, extensive research is necessary to identify and characterize suitable bacterial species and how best to exploit them.

PENGARUH KOMPENSASI, LINGKUNGAN KERJA DAN BUDAYA KERJA TERHADAP KINERJA KARYAWAN PABRIK GULA ASSEMBAGOES DENGAN KEPUASAN KERJA SEBAGAI VARIABEL INTERVENING

Companies cannot be separated from having quality human resources; this will have an impact on the sustainability of the company's goals, superior, professional and competitivehuman resources which will have a positive impact on the company's success. The aim of this research is to analyze and test the influence of Compensation, Work Environment and Work Culture on the Performance of Assembagoes Sugar Factory Employees with Job Satisfaction as an Intervening Variable. This research is explanatory research. The populations in this study were contract employees of the Assembagoes Sugar Factory. The sampling technique is determined by quota sampling. The data analysis and hypothesis testing in this research used the Structural Equation Model - Partial Least Square (PLS-SEM). The results of the direct influence hypothesis test using the Smart PLS3.0 application, show that Compensation has a positive but not significant effect on Job Satisfaction, Work Environment has a positive and significant effect on Job Satisfaction, Work Culture has a positive and significant effect on Job Satisfaction, Compensation has a positive but not significant effect on Performance, work environment has a positive but not significant effect on performance, work culture has a positive and significant effect on performance.

Slow feature‐constrained decomposition autoencoder: Application to process anomaly detection and localization

SummaryDetecting anomalies in manufacturing processes is crucial for ensuring safety. However, noise significantly undermines the reliability of data‐driven anomaly detection models. To address this challenge, we propose a slow feature‐constrained decomposition autoencoder (SFC‐DAE) for anomaly detection in noisy scenarios. Considering that the process can exhibit both long‐term trends and periodic properties, the process data is decomposed into trends and cycles. The repetitive information is mitigated by slicing and randomly masking certain trends and cycles. Dependencies among slices are constructed to extract intrinsic information, while high‐frequency noise is reduced using a slow feature‐constrained loss. Anomalies are detected and localized through a reconstruction error strategy. The effectiveness of SFC‐DAE is demonstrated using data from a sugar factory and a secure water treatment system.

Compressive Strength Analysis of Renewable Mortar after Portland Cement Replacement with Waste Ash

There are many environmental problems caused by factory waste. Sugar factory waste, in the form of bagasse ash, and PLTU factory waste, in the form of fly ash, are currently in the spotlight of science studies. This study used waste bagasse and fly ash to substitute Portland cement as the main ingredients for mortar. Baggash and fly ash waste were collected, processed, and then used to replace cement by up to 40% to determine to what extent they could be used in brick masonry work, wall plastering, and masonry paste. Experimental tests were carried out on mortar cube samples measuring 5×5×5 cm, comparing four types of samples consisting of Portland cement, bagasse ash, and fly ash. The compressive strength results were obtained after 28 days. Normal Mortar (MN=11.75 MPa) had higher compressive strength than the substitute mortar types MA (3.23 MPa), MB (3.09 MPa), and MC (2.98) MPa. According to SNI 6882-2014, MA, MB, and MC mortars can be used as O-type mortar (2.4 MPa). Therefore, they can be applied to wall plastering or walls not bearing loads.

Heritage and identity: The vernacular transformation of de tjolomadoe

Background: This research paper focuses on the adaptive reuse of the De Tjolomadoe (Colomadu) heritage sugar factory within the field of vernacular architecture. Method: Utilizing qualitative research methods such as in-depth interviews, site observations, and archival analysis, it examines the preservation of industrial heritage through its integration into vernacular architectural practices, yielding insights for sustainable development. Findings: The De Tjolomadoe factory, a prominent Indonesian historical and cultural landmark, serves as a compelling case study in adaptive reuse, offering significant findings. Firstly, it illustrates how adaptive reuse effectively preserves cultural identity by seamlessly blending vernacular design elements and traditional building techniques, thereby maintaining a strong connection to its historical and cultural heritage. Secondly, the De Tjolomadoe case exemplifies adaptive reuse as a sustainable development strategy. By utilizing local resources and adhering to vernacular construction methods, the project minimizes environmental impact while generating economic and social benefits for the community. Community engagement emerges as a crucial factor in the success of adaptive reuse projects, as actively involving local communities ensures the authenticity and relevance of such initiatives. Moreover, the transformation of the De Tjolomadoe factory into a cultural destination underscores its substantial economic impact on the region. Similar adaptive reuse projects have the potential to boost tourism, stimulate local economies, and preserve cultural heritage. Conclusion: The lessons drawn from the De Tjolomadoe case offer practical insights and principles guiding future adaptive reuse endeavours, emphasizing cultural preservation, sustainability, community participation, and economic viability. Novelty/Originality of this article: These findings contribute to the growing knowledge base on the adaptive reuse of industrial heritage sites within the context of vernacular architecture, inspiring and informing initiatives aimed at revitalizing our industrial heritage for future generations.

Availability, distribution and quality of agro-industrial byproducts and compound feeds in Ethiopia

Livestock production is a major contributor to the national economy in Ethiopia, of which ruminants, particularly cattle, are the dominant and most important livestock species. Limited supply of quality feeds is a major constraint to the improvement of livestock production in Ethiopia. The expansion of agro-industries in Ethiopia, over the last three decades, has created an opportunity for an increased supply of agro-industrial byproducts as a source of feed for livestock. This study was conducted to assess the availability, distribution, and quality of agro-industrial byproducts and compound feeds in Ethiopia. About 310 flour mill factories, 194 oil factories, 13 brewery factories, 7 sugar factories, 4 malt factories, 2 meat and bone meal processing plants, 8 limestone factories, and 112 feed processing plants were surveyed to assess the availability and distributions of agro-industrial byproducts and compound feeds. A total of 757 feed samples were collected for evaluating nutritional values. The annual production of agro-industrial byproducts ranges from 18,065 tons DM/year (abattoir byproducts) to 3,092,035 tons DM/year (malt byproducts) and the total annual production of the different agro-industrial by-products amounts to 5,245,854 tons DM. The annual production of compound feeds was reported to be 5,812,608 tons DM. All agro-industries are processing under their capacity, ranging from 11.7% in sugar factories to 93% in breweries. Shortage and seasonal fluctuation of supply of raw materials (34.8%), high price and price fluctuations of raw materials (17.5%) and electric power interruptions (17.5%) were the major challenges faced by different agro-industries. The crude protein (CP) concentrations of agro-industrial byproducts ranges from 6.2% in maize grain screening to 15.9% in wheat bran for flour mill byproducts; 28% in cotton seed cake to 49.7% in groundnut cake for oilseed cakes and 14.8% in areqe atela to 24.8% in brewery spent grains for brewery and local distillery byproducts. High protein or energy contents of agro-industrial byproducts indicated their potential to be utilized in intensive livestock rations. Thus, it is necessary to create enabling conditions to allow the existing agro-industries to operate at full capacity and to attract new ones into the business to boost the production and availability of agro-industrial byproducts needed as main inputs to manufacture compound feeds.

Designing heat economy for a beet sugar factory with reduced evaporator station load from sugar house vapor intake

Designing heat economy for a beet sugar factory with reduced evaporator station load from sugar house vapor intake

Kedampingan Hewan Penghela pada Industri Gula di Jawa Abad XX

This research discusses the relationship of draft animals and humans in Java has been historically intertwined, reaching a turning point at the end of the 19th century. This period saw the initiation of various industries, especially sugar factory, ethical awareness regarding the welfare of animals, as well as a collective awareness of the identity of a new of Indonesian society and workers. Consequently, the concept of human-animal relationship periodically undergoes changes to harmonize with the new world order. As a result, the values of human-animal relationship, and especially humans with nature, are now characterized by relationships that are always based on transactional relations. This results in the dissolution of the identity of Javanese society, which has a close relationship with nature and animals in line with the concept of “underworld and upperworld”. This article uses historical method with the approachment of environmental history. The primary sources for this article are contemporaneous newspapers, PG Gondang Baru’s 1958 Annual Report, and other documents in the form of contemporaneous photographs, complemented by other secondary references.